Fish Friends, a fairly new Playdom game, and Mall World, a well-made fashion game that appears to be by an indie developer called 50 Cubes, top our list of the 20 fastest-growing Facebook apps with fewer than a million users.

We cover the games in depth over at Inside Social Games. Also note on the AppData top 20 list, below, that Facebook hasn’t updated the stats for several of these apps for several days, keeping the reported numbers a bit lower than usual:

	Name	MAU	Gain	Gain, %
1.	Fish Friends	505,480	+232,227	+84.99
2.	Mall World	401,686	+214,043	+114.07
3.	iKarma	440,775	+173,151	+64.70
4.	Akinator	551,225	+130,524	+31.03
5.	Takipçilerim	203,906	+101,557	+99.23
6.	Hızlı Yaz	249,918	+92,731	+58.99
7.	Big Prize Giveaways	249,044	+84,500	+51.35
8.	Premier Football	893,658	+84,178	+10.40
9.	What Song Was #1 on your Birth Date?	760,205	+80,652	+11.87
10.	Car Madness	533,794	+73,880	+16.06
11.	Hugglicious	473,809	+72,496	+18.06
12.	Your Japanese Name	844,296	+70,131	+9.06
13.	Evony	202,660	+68,257	+50.79
14.	Agatha’s Horoscopes	163,936	+67,944	+70.78
15.	武俠風雲	275,226	+65,094	+30.98
16.	Decorative Writing	876,054	+63,702	+7.84
17.	My Tribe	314,296	+60,527	+23.85
18.	Know Your Name	125,205	+59,229	+89.77
19.	FarmVillain	405,014	+56,929	+16.35
20.	Quizazz	786,309	+56,522	+7.74

At number three, iKarma is picking up users with a flashy combined horoscope and luck interface, along with viral sharing aimed at the superstitious — just share this app with your friends, and your luck is bound to improve! Or, at least, your luck as reported by iKarma.

Akinator is a French quiz game, formerly only in that language, though it appears to have expanded into English now. The “Akinator” is a genie that plays a version of 20 questions, although it appears to pre-determine the category you’re guessing in. Following it is Takipçilerim, which is a Turkish-language quiz app, while Hızlı Yaz is also Turkish but appears to be a typing game.

Big Prize Giveaways is exactly what it claims, although what qualifies as “big” is, obviously, in the eye of the beholder. As our regular readers may remember, a similar concept recently helped Marketplace gain millions of users.

Take a look over the rest of the list — there are several more interesting apps that have just begun to grow, including Decorative Writing, which is the calligraphic version of Graffiti, and FarmVillain, an increasingly successful wall-posting parody of FarmVille.

Recent media reports from China suggested that Facebook is looking to enter the country even though it is currently blocked. The reason, it turns out, is that local Chinese media misunderstood a job posting by Watercooler, a Facebook application developer active in the country.

And, yet, we hear whispers that Facebook traffic is growing in the country.

First, the Facebook-China rumor mixup, as described by Marbridge Daily:

According to the sources, Watercooler, a U.S.-based developer of social games for Facebook which recently set up China headquarters in Beijing, posted a recruiting notice seeking staff for “development of social games for Facebook”, meaning “for games to be featured on Facebook”. The posting was apparently misconstrued by a popular Chinese gaming industry portal as indicating that it was Facebook itself that was recruiting for a new China office. Other Chinese news media then reportedly republished the story or variations of it.

The basic reason why Facebook would be looking at entering China is that it is by far the largest market that Facebook has little or no presence in. The company has been thinking about it for years, we’ve heard consistently (and unsurprisingly). It bought the domain Facebook.cn, although that URL doesn’t display anything, and the purchase could have easily just have been a defensive move to protect against domain speculators.

Between heavy censorship, ownership laws, other regulatory complexity, massive local competition, a potentially global public relations nightmare and a range of other issues, Facebook would likely face substantial obstacles if it tried to more aggressively enter the Chinese market. At least that’s the few of people we talked to in China thought. There is no middle ground between working with the Chinese government or against it; we’ve heard that Chinese censors blocked Facebook within 72 hours of when its Simplified Chinese translation became available, for example.

In the meantime, the country currently has 61,000 monthly active Facebook users out of a population of more than 1.3 billion — around what it has had for many months. It’s not clear how accurate that number is, as privacy software typically changes IP addresses and other information to identify users as coming from somewhere else in the world.

Still, if any outside web company has a shot at getting market traction in China — aside from all the major issues, above — Facebook is probably it. Although the company has not made headway in countries with distinct business and cultural barriers with strong local competitors, including Russia, Japan and Korea, it has grown everywhere else. It’s still too early to know how many local competitors can hold their own against Facebook’s internationally strong position in the long run. But at this point, these countries appear to be islands in a Facebook ocean, and the water is continuing to rise.

Mainland Chinese users are separated by censorship, dialect and taste from Chinese speakers in many other parts of Asia and the world. Yet it is possible that the large number of Chinese-speaking Facebook users (not to mention the Chinese-language games and other apps) could help make the site interesting to mainland users if they could get access.

Facebook has been getting big in Chinese-speaking parts of Asia, including Taiwan, Hong Kong, Singapore and other major cities. As of the beginning of this month, there were around 85 million monthly active Facebook users in the region, according to our Global Monitor Report – available to Inside Facebook Gold members – up 75 million from last month. We don’t have specific numbers on how many of those users are using the site in Chinese, but there are certainly many. Facebook is getting more focused on the Southeast Asian market, at least, recently beginning to post job listings for a new office in Singapore, likely focused on sales.

Now, here’s some on the record thoughts on the possibility Facebook entering China. Here’s Beijing-based Kaiser Kuo‘s view of Facebook’s PR problem if it somehow worked with the government to enter the market:

Whatever the real reasons for Google’s actions, the dominant narrative is says they stood on their principles and defied a censorious regime. Any move Facebook made that involved bowing to Chinese censorship would bring down the indignant wrath of every rights organization you can name. Facebook’s already a lightning rod, and critics are always ready to jump all over it for so much as an unpopular interface change. Imagine what they’d do if a hypothetical Facebook China hired a team of in-house censors, like their Chinese competitors are obliged to have, and started scrubbing every positive mention of Google, like Kaixin001 and Renren were compelled to do just a few weeks ago? Putting user information on Chinese IDCs would be asking for trouble, too: Facebook would be legally obliged to turn over personal information to Chinese law enforcement, just as Yahoo! had to do in the Shi Tao case. The late Congressman Tom Lantos called them “moral midgets” for that, you may recall.

And then there’s the competition issue. More, from Kuo:

Even if Facebook did decide to bite the bulled on censorship-related issues and go ahead with a push into the PRC, critics be damned, it’s difficult to see what they could really offer Chinese users that they aren’t already getting from Chinese social networks like Renren, Kaixin001, QZone and 51.com. These sites have real momentum already, and users have built out extensive networks. They’re already awash in social games and innumerable other apps. Many Chinese users already belong to multiple SNSs. Granted, there would be tens or even hundreds of thousands who value connectedness with an international network and would therefore see real value in Facebook. But we’re talking about a market where you need tens of millions of users to be a real player.

Another China watcher, Bill Bishop, proposed a different strategy that might be more worth Facebook’s while:

Instead, provide free VPN and other filter-bypassing services. A meaningful number of Chinese users will flock to your products if they can access you easily. You will then have a decent base of Chinese users which, given your sophisticated ad-targeting capabilities, you will eventually be able to monetize, with a much higher margin than if you were operating in China.

The topic of censorship leads us to the other item we heard: Facebook is actually growing in China, but through mobile devices. The government is somehow censoring out whatever it feels appropriate via the existing mobile censorship apparati it has with those companies. From the China-based people we’ve spoken with, however, no one can access Facebook via mobile devices and no one has heard this rumor.

Facebook has been expanding payment options for Facebook Credits, its universal virtual currency used in Platform applications, in recent months. Today, it is partnering for the first time with two offer providers so users can earn Credits without having to pay directly.

For users, this means another way to get Credits without paying — this may increase spending on Credits for social games and other applications on Facebook. For developers, that means Credits might be able to bring in more money than they have to date. And for other offer providers, Facebook is now more of a direct competitor, although the payment option is only in early beta testing at this point, and the company’s long-term plans are not yet clear.

Offers are simply online ads, usually drawn from ad networks elsewhere on the web, that let users buy subscriptions and goods, complete surveys, or take other actions in exchange for virtual currency. They were a key early way for social applications to monetize on the platform, although direct payments currently comprise the vast majority of app revenue today (check out our Inside Virtual Goods report for more details on the social gaming payments ecosystem breakdown). Monetization services companies have typically included offers in an “offer wall” as a separate page in apps, beneath direct payment options like PayPal and mobile payments.

However, in the early days of the platform, most offer providers and game developers did not effectively filter offers for quality. So, many of the scammy ads you see on other web sites — quizzes that trick you into mobile phone subscriptions, surveys that craftily collect your personal information, etc. — were commonly found on Facebook. Many established brands stayed away from the ad product as a result; the scammiest offers were often the most lucrative, and so the most popular with many developers.

Facebook began cracking down on low offer quality last summer and fall, especially after widespread media exposure of low offer quality. While developers and monetization providers have worked to filter out bad offers and provide more good ones, Facebook’s move today is going a step further.

The New Offers Test

The current two partners are TrialPay and Peanut Labs, both of whom have made notable efforts to provide higher quality offers for the industry. They are providing the relationships with the offer advertiser, as well as other back-end support, like customer service. The first three developers to test Credits-offers integration are CrowdStar, Playdom and RockYou. Facebook is not disclosing the revenue share with its offer partners.

Offers will be available around the world. The number of Credits that can be earned is dependent on the type of offer, as usual, but ranges from 1 to well above 100.

Ethan Beard, head of Facebook’s developer network, tells us that Facebook has hand-picked specific offers from the partners to run within Credits, using offer quality standards that are higher than what it requires of third parties. All offer payments will be instant (or close to it); excluded offer categories include ads for credit reports, auto-recurring magazine subscriptions and most other recurring online and mobile subscriptions. “We wanted to take a conservative approach with this test” he says. “We work hard to make sure all advertisers and other providers are in compliance.”

Beard sees this test as an early, relatively simple step in understanding how the company can help provide more value to users, developers and advertisers on Facebook. “What we do in the future will be determined based on the information we gather here,” he tells us. “We want to get a better understanding of how we can help our developers be more successful in driving business on the platform.”

Following a lull in growth in February, most of the Arabian Peninsula (plus Egypt) sped ahead in March, adding 640,280 new monthly active users. That’s an 8.2 percent increase, to a total of 9,830,480 users for the sub-region, which we’ve broken out from our latest Facebook Global Monitor data from Inside Facebook Gold.

Saudi Arabia is the stand-out country here. When we discussed February’s figures last month it had achieved only 5.8 percent growth; as you can see in the table below, it grew an impressive 13.4 percent in March. And with its relatively low penetration, the country still has plenty of room to accelerate in the future.

More surprising is the second-fastest grower, Israel. At 35.9 percent penetration, Israel seems like it should be nearing its limits — most countries top out as they approach 40 percent. However, that may not prove to be true for Israel, which is small and tightly-knit at 7.3 million citizens. We’ve observed that smaller countries tend to have the highest penetration rates — at least up to this point in Facebook’s growth. For reference, the most-penetrated country in the world is tiny Iceland at 54.6 percent, while the lumbering United States is still at 37 percent.

Most of the remaining countries in the table also grew faster in March. The exception is Egypt, which performed better in February — or did it? Facebook’s figures usually lag behind by several weeks. So the slowed growth we’re seeing now might actually be the result of a fatwa issued on Facebook by an Egyptian cleric in early February. The social network has unintentionally become a political weapon in the country; more recently, the head of the opposition sent out a plea for reform via Facebook.

The Middle East is not a terribly important region by size alone, but Facebook has put some effort into securing an advertising deal for its own definition of the Mideast, which stretches from Morocco to Pakistan. For our own numbers, we cover the Maghreb with Africa (look out for that post next week), and Pakistan with Asia.

You can find more detailed growth stats and forward projections for the next year on 96 countries in the full Facebook Global Monitor report, available through Inside Facebook Gold at gold.insidenetwork.com/facebook.

Facebook announced it would start a Ph.D. fellowship program — and yesterday the company announced who these first fellows would be during the 2010-11 school year, as chosen from hundreds of applications. Finalists appear to specialize in areas that Facebook has been either addressing or planning to address.

Here they are, in alphabetical order:

Vinayak Borkar focuses on Cloud Computing and is currently studying at the University of California at Irvine. Specifically, he researches “ways to improve distributed computing platforms for data analysis,” which is a key part of how Facebook operates. In addition to his academic pursuits, Borkar previously worked at several software companies and co-founded Black Titan Software in San Jose, California.

Parmit Chilana studies social computing at the University of Washington in Seattle, specifically researching human-computer interaction. She’s hoping to develop her ideas for “crowdsourcing help for web applications in a real-world setting” while at Facebook. Parmit has also studied library and information science and computer science.

Leslie John studies behavioral economics at Carnegie Mellon University in Pittsburg, Pennsylvania. Her area of research encompasses “new dimensions of privacy and how people decide what information to disclose” and hopes that the Facebook fellowship will help her to “extend her research to the context of social networking.”

Mladen Kolar is also studying at Carnegie Mellon, though his focus is machine learning, specifically, “the structure of networks and how they change and evolve over time.” He hopes to “provide insight into complex patterns underlying high-dimension and noisy data,” at Facebook. Kolar has previously studied electrical engineering and computing.

Yaron Singer studies Internet economics at the University of California at Berkeley focusing on algorithmic game theory and mechanism design. Singer previously founded an advertising network for social media, Bidwave, and during his Facebook tenure plans to research “how to build a platform where people view ads as beneficial recommendations.” He preiously studied mathematics and computer science.

In addition to the prestige of working with Facebook for a year, each of the five fellows will receive a $30,00 stipend, plus conference travel and other perks. Twenty-two other finalists received $500 from Facebook as well.

In the blog post announcing the winners, Facebook Director of Engineering Greg Badros wrote that Facebook started the fellowship program “because the academic community plays a central role in addressing many of our most challenging research questions on topics ranging from cloud and social computing to Internet economics and machine learning.”

The end goal for Facebook, Badros wrote, is for the fellows to help the company develop solutions directly applicable to the social web and Facebook.

For those of us you that didn’t get your Coachella Valley Music And Arts Festival tickets for this weekend’s uber-concert in southern California, 5 Gum is offering you a way to enjoy the festivities live through your Facebook page. Coachella and the Wrigley brand have teamed up to offer three live streams from the show this weekend, with special behind-the-scenes content and on-demand material appearing May 3.

Company promotions at concerts are nothing new — but social media is, relatively speaking. And as brands have gotten more comfortable marketing on Facebook in the past couple of years, their tie-ins with concert marketing have gotten more ambitious. Levi’s began live-streaming a concert venue at South by Southwest last month — a venue that it had already been involved with for years. Microsoft is planning a big push for summer concert ticket giveaways on Facebook together with Live Nation. Odwalla meanwhile, has its own Facebook promotion already going for Coachella and other festivals this summer.

This latest offering from 5 Gum is being run to promote the company’s release of two new React flavors (Mint and Fruit) and lets fans of the brand create a custom itinerary based on a select list of artists. Fans can preview the artists work through both Facebook and MySpace buttons housed in the application(which was developed by Appssavvy) and piece together their favorite bands from the list to post to their news feeds. The festival will then be streamed live through three different channels, one of which will be in HD, and fans will be able to interact with each other during the concerts through Twitter and a real-time chat function built into the site.

The Coachella festival has become one of the larger music events of the summer concert schedule, and this year’s lineup features everyone from big names like Jay-Z and the Gorillaz to up-and-coming indie bands, as well as a much-anticipated reunion from alternative rock pioneers Pavement. The $270-plus 3-day passes sold out long ago, with prices for tickets on sites like Stub Hub reaching as high as $4000 right now. So the Facebook application could gain more prominence as a way to give every Facebook user a chance to join in the festivities.

There are currently a little more than 40 artists listed in the Coachella application, but artists are being added and updated as this weekend’s festival approaches. Once you’ve entered all the bands you’d like to check out, you can go back to watch the groups through the live streams. And there will still be plenty of content available even after the last band has played — 5 Gum will be posting exclusive content on their Facebook fan page, including interviews, backstage footage, on-demand performances and complimentary downloads starting May 3.

The big Pacific Rim countries once again led the greater Asian region in monthly active user growth for the month of March. The region as a whole has grown by around 6 million people over the last month to slightly above 85 million monthly active users, according to the latest Facebook Global Monitor data from Inside Facebook Gold.

The top 10 list of fastest-growing countries, below, is little changed in its upper rankings from February’s growth figures, except that Malaysia has moved up to third on stronger growth, while India has dropped to fourth.

Indonesia, the top grower, actually leads the rankings this month for the entire world with 1,933,020 new users. But, with about 228 million people, the country has plenty of room to grow; the gains in the Philippines and Malaysia, which are both significantly smaller, seem relatively more impressive. Note that Malaysia has also topped 20 percent penetration, a relatively high rate, and a point where some countries start slowing down.

With its Friendster-inspired legacy of social networking, it’s not hard to see why the Pacific Rim is growing — as well as East Asia in general, which is following Taiwan’s lead onto Facebook. But India’s growth rate has inexplicably slowed after showing promising signs over the past few months.

At just 0.7 percent penetration, it doesn’t seem at all certain that India will become an important country for the social network anytime soon. Alternately, Facebook, which just opened an office in Hyderabad, could become more aggressive about spreading itself in India, to the detriment of Google’s Orkut.

India’s neighbor Pakistan also registered slower growth in March, while Vietnam and Japan, both low-penetration countries, made slightly better showings than in the past. We should also note that while Facebook is not entirely blocked in Vietnam, numerous reports suggest that government censorship is interfering with user access to it in the country:

Taking the Asian region as a whole, the growth rate has fallen each month this year; the region grew about 7.5 percent in March. That leaves it with an audience of 85,342,280 people on Facebook, about 2.3 percent of its 3.75 billion citizens — although it should be noted that Facebook’s advertising tool, from which this info is sourced, usually runs a few weeks behind. You can find more detailed growth stats and forward projections for the next year on 96 countries in the full Facebook Global Monitor report, available through Inside Facebook Gold at gold.insidenetwork.com/facebook.

Mayors will sometimes use their Facebook Pages to bypass local media channels or government bureaucracies in order to communicate directly with their constituencies, or provide hard-to-find information, we found recently when we looked around Facebook for mayors’ Pages. As part of our ongoing series of how government entities use Facebook, we have reviewed a range of mayors with Pages — we know that these figure prominently in elections, but what happens once the candidate becomes the official?

We looked at about a dozen such Pages to see what they were doing. For the sake of easy comparison, we only looked at the Pages of U.S. mayors, although there were several Pages for mayors in other cities around the world, such as Talisay City, The Philippines mayor Doc Eric Saratan’s Page (about 1,100 fans), as well as elsewhere, like Karachi, Pakistan Mayor Syed Mustafa Kamal (about 68,500 fans).

Here’s a snapshot of some US mayors and their fan counts: Los Angeles Mayor Antonio Villaraigosa had just 2,500 fans, Houston mayor Annise Parker had 4,700 fans, the mayor of Wentzville, Missouri Paul Lambi had 392 fans, Mayor Jim Byard of Prattville, Alabama had 572 fans, Detroit Mayor Dave Bing had 728 fans, Buffalo, New York’s Mayor Byron W. Brown had 2,200 fans, Seattle Mayor Mike McGinn had 855 fans, Utica, New York Mayor David Roefaro had almost 2,100 fans, Memphis Mayor A.C. Wharton had 6,300 fans and San Antonio Mayor Julián Castro had 3,500 fans.

The Wall seemed to be the main hub of activity for most mayors — that’s where they posted the bulk of the information they shared on Facebook, as did their fans. More often than not the mayors posted news links or links to city web sites, blogs/notes and sometimes videos. Several also frequently posted notes and photos were a mainstay on most of the Pages.

Generally speaking, the mayors that used their Pages to speak specifically to their constituents in “localized” terms were the most successful, both in terms of the number of fans and the amount of interaction — and this was not limited to a city’s size. For example, Los Angeles has almost 4 million residents but Mayor Villaraigosa rarely updates his Page and consequently had a paltry 2,500 fans compared to Mayor Brown’s frequently updated Page with a fan base of 2,200 in Buffalo, New York, a city with about 271,000 residents.

Even cities with smaller bases to work with aren’t always able to maneuver fans to their Pages, as evident with Mayor Paul Lambi’s 392 fans from among about 23,800 residents in Wentzville, Missouri or Mayor Jim Byard’s 570 fans from the 32,500 residents of Prattville, Alabama. Both posted hyperlocal information regularly, Lambi going so far as to post his location, “Every Wednesday morning I meet with the City Administrator for a briefing. This morning, we’re meeting at I-Hop.”

Rather, what seemed to make or break these mayors’ Facebook Pages was the combination of genuine interactivity combined with smart promotion of this medium.

San Antonio, Texas Mayor Julián Castro, who we’re told runs the Page himself, seems to have accomplished this balance nicely, as with a city of over 1.3 million people and 3,500 fans, he had one of the largest fan Pages we saw. From what we observed on the Page, Castro managed to almost daily promote local issues like the influx of shoppers from Mexico over Easter weekend, or localize larger issues such as the Census, prompting fans to comment quite often (he occasionally comments back). There are lots of photos and videos, notes are added at regular intervals and he often shares news links on the Wall to prompt discussion.

We spoke to Christian Archer, Castro’s 2008 campaign manager and current political aid to the mayor for his Facebook Page, about how it figured in the election and how Castro now uses the Page to highlight his pet issues. Castro has been enthusiastically using different types of technology since his campaign, Archer tells us, noting not only Facebook, but also pointing to live town halls on his web site, Flip videos, Twitter, YouTube and Flickr. During the campaign Castro began using his personal Facebook profile to communicate with supporters, and once elected, he created the Page and has been trying to migrate fans there ever since, Archer said.

“One of the promises we made during the campaign was (that) this Page wasn’t just going to be for the election,” Archer said, noting that Castro is the first San Antonio mayor to have a Facebook Page, although to be fair, there’ve only been two other mayors since Facebook was founded in 2004. “The percentage is still not huge that check our Facebook — it’s not going to win or lose an election — but it is vital to the people who are online.”

Castro’s Facebook Page was promoted on campaign literature and the same is being done now that it’s a part of the mayor’s official communication platform, Archer tells us; this may be one reason why Castro’s Page is much larger than others we saw. Growing the Page was important because Archer said Castro wanted the interactivity available on Facebook to constituents 24/7, allowing them to get involved without having to be activists and also because social media has become a way for the mayor to promote causes that might not draw the attention of the local media.

“A lot of this stuff will never get covered. We’re able to communicate a lot of smaller things that might not make the 6 o’clock news, but yet are still important,” Archer explained.

The amount of time and attention spent on Facebook Pages seemed to have a direct impact on the number of fans and interactions, but this wasn’t always the case. Sometimes mayors who only sporadically tended to the Page had larger followings than others who were on Facebook almost daily.

Case in point, Seattle Mayor Mike McGinn constantly updated his Page but, in a city of almost 600,000 he only squeezed out 855 fans; meanwhile, Utica, New York Mayor David Roefaro added 2,000 fans from a city of 58,000 people. Lots of factors could have contributed to this difference, perhaps one Page has been around longer than the other or there are links to the Page on city web sites, but such differences are curious, nonetheless.

As previously mentioned, the quality of information on the Pages was also essential to success on Facebook. Houston Mayor Annise Parker was elected to represent 2.2 million residents and does a decent job of talking about her work on Facebook to her 4,700 fans, while Memphis Mayor A.C. Wharton’s constituency of 670,000 has awarded him about 6,300 Facebook fans. Even more interesting, Detroit’s Mayor Dave Bing was once a popular basketball player, an entrepreneur and now mayor but has just 727 fans in a city of more than 912,000 people. What’s more, Bing posts regularly and includes pertinent government documents among his photos for people to more easily access information.

There are lots of questions here that don’t yet have clear answers. Are some cities more Facebook-centric than others? Do some mayors promote their Pages more than others? Do different regions of the country feel more comfortable as fans of politicians? Are mayors just less interesting to Facebook users than a President, Governor, Congressmen or Senator? Is it just that some politicians are more beloved than others?

Facebook users currently seem less compelled to become fans of their mayors than of other politicians, for whatever reason. Some cities’ mayors don’t even bother to have Facebook Pages. New York’s Michael Bloomberg is a good example (but he does have Twitter, YouTube and Flickr). Creating a successful Facebook Page for mayors seems to be part work (updating, etc.), part promotion (including it on web sites and other official literature) and part luck (do people in your city care about mayors on Facebook?). All that said, we expect mayors, and their campaigns to do a better job figuring out how to use Facebook in the future.

For more tips on using Pages and other Facebook features to build fan bases, be sure to check out our Facebook Marketing Bible and our new subscription service for premium reports and data, Inside Facebook Gold.

The last week was a big one for Zynga, which found a new hit in Treasure Isle. The treasure-hunting game picked up an impressive 2.7 million daily active users to lead this week’s list of fastest gainers by DAU, although it won’t necessarily hang onto all of its new users.

Both Treasure Isle and Hotel City, by Playfish, are new to the field. Though not fads quite at the scale of farming or fish games, each is now the leader of their own small group of similar pre-existing games, just as Playdom’s Social City recently shot up to become top dog in the city building category.

We’ll talk about the rest of the games in more detail at Inside Social Games. Here’s the full AppData list:

	Name	DAU	Gain	Gain, %
1.	Treasure Isle	4,383,461	+2,730,691	+165.22
2.	Hotel City	2,638,497	+942,891	+55.61
3.	Birthday Cards	1,808,120	+374,046	+26.08
4.	Daily Photo	484,163	+203,786	+72.68
5.	Zoo Paradise	808,372	+178,983	+28.44
6.	Facebook for iPhone	16,129,391	+173,436	+1.09
7.	Family Feud	414,659	+172,410	+71.17
8.	Facebook for BlackBerry® smartphones	9,596,600	+166,574	+1.77
9.	Happy Pets	1,720,771	+165,795	+10.66
10.	LivingSocial	161,029	+120,081	+293.25
11.	Happy Aquarium	4,296,714	+115,003	+2.75
12.	Happy Island	2,646,166	+114,452	+4.52
13.	Causes	1,147,660	+113,834	+11.01
14.	Mall World	131,472	+107,106	+439.57
15.	Tiki Resort	940,072	+89,556	+10.53
16.	Ninja Saga	934,149	+87,213	+10.30
17.	Your Luck [daily]	440,300	+80,465	+22.36
18.	Lover Of The Day	130,508	+80,403	+160.47
19.	Pet Society	4,079,277	+80,057	+2.00
20.	Entrevista tus Amigos	322,557	+79,704	+32.82

Birthday Cards, the largest gifting app on Facebook, is continuing a long slide in monthly active users, recently down to 37 million. The DAU picture isn’t quite as clear. Cards’ DAU numbers have spiked up and down over the past month, with only the last week becoming stable enough to show the app averaging 4-5 percent of its MAU as DAU.

The next app down is Daily Photo, which like Cards isn’t really growing. Our DAU snapshot does reveal what appears to have been a short-lived suspension of the app by Facebook, though, with the recovery resulting in the 203,786 DAU gain you see above. Comments by users suggest that the app may be pushing too hard with its automatic wall posts and advertising.

Skipping down to number ten, LivingSocial looks as if it may have begun an ad campaign to stem its own slow losses. Actually, there are only two non-game apps on the list that are making real gains: Your Luck [daily] and Lover Of The Day, both of which are newer, fairly fluffy apps. Your Luck gives you a straightforward percentage of your supposed good (or bad) fortune, while Lover Of The Day picks out a random friend to be your “lover”, regardless of age, sex or familial relation.

Facebook is testing out a new “Questions” app, and not while not many details are available about it now, the concept is intriguing – and it’s perhaps a foreshadowing example of how developers should expect to see Facebook testing out more of its own apps this year.

The Questions feature appears above advertising on the right-hand column, and includes links to provide an answer, or ask your question. It also shows you the name of the person who asked a question — presumably a current Facebook friend, or someone in your geographic area, perhaps — with a link to their profile. While Facebook has run various interactive elements in this space before, like “become a fan,” this is the first time it has put direct user-to-user interactions in it. In terms of how the app will function, we’re guessing it will access user profile data about friends to decide which users will see which questions, like what Aardvark does.

The bigger picture, on that point, is that “Questions” appears to be a new communication channel, distinct from the news feed, messages, invites and notifications. It’s not clear what else Facebook might want to do with it. Perhaps we’ll start seeing questions and answers appear as news feed stories, for example, or somehow give third party applications, Pages and Facebook Connect sites access to it for their own questions, asked from their own destinations?

The right-hand column placement also suggests Facebook may want to provide companies and other organizations with access to the service for a fee of some sort. Like Facebook sells “Sponsored Events” as an ad unit, one can easily imagine “Sponsored Questions” going in here. Or, Facebook perhaps thinks Questions is a feature that will get users paying more attention to the right-hand column than they have been, thereby driving up clicks on ads?

All these questions imply that the company will need to carefully control privacy around the feature, as the new channel is an obvious place for inappropriate or sensitive questions and answers, that users probably don’t want to have made widely available.

Facebook’s Blake Ross gave a little more background yesterday on Quora:

Facebook’s experimentation in this “space” is actually a direct result of internal circumstances at the company rather than all this recent outside activity. For the last few years, we didn’t have enough engineers to make significant, sustained investments in our applications (e.g. photos and events). Earlier this year, we finally got comfortable enough with our recruiting numbers to reorganize the product engineering group into dedicated application teams of 4-5 people each. That’s why you’re suddenly seeing improvements to applications that haven’t evolved in years, such as our recent launch of higher res photos. One of our app teams is charged with experimentation and we decided to pursue this vision of real-time Q&A now that the resources were finally in place.

User-generated question and answer services have been around for years. But a couple very interesting ones have launched recently that try to take advantage of social connections to provide better answers. One is Aardvark, real time-driven service that was recently bought by Google. It lets you type simple questions into a variety of interfaces — instant message was the main one — then it sends your question to your friends who had the most relevant interests and expertise. Facebook profile data was a key way that it figured out which person to send which questions to.

A group of former Facebook employees have also recently started a site called Quora, that provides an easy-to-use interface for asking and answering questions. It relies entirely on Facebook for social features; it automatically has you “follow” all of your friends on the service without saying so, for example. By using Facebook, it retains the real-world connections that most people have on the service.

We still don’t have many details on Questions. But we do know one thing: Facebook is investing more in its in-house apps, something we predicted we’d see more of this year just last week.

[Image via All Facebook.]