[Editor's Note: The following stats are excerpted from Inside Facebook Gold, our membership service tracking Facebook's business and growth around the world. Visit Inside Facebook Gold to learn more about our complete data and analysis offering.]

As the Facebook platform ecosystem continues to grow and diversify, it has become increasingly important — and interesting — to note which users are engaging most with today’s popular apps. We looked at demographic data for 18 different leading apps by multiple developers. Based on the data we’ve collected, the demographics for today’s top apps are not entirely what you’d expect. While users for these in apps generally trend young and female, this is not the case for every single app in our selection.

Texas HoldEm, by Zynga, is an example of one app that has a significantly more male than female userbase. 72.7% of that app’s users are male, compared to an average of just 38.2% across all the apps we surveyed.

On the other side of the spectrum, Sorority Life is an app that has an understandably more female than male audience. 91.7% of that app’s users are female, compared to our selection’s average of 60.8%.

Farmville, Zynga’s hit game that has stayed at the top of the leaderboard for months now, also trends slightly more female, with women making up 57.9% of its audience. While much has been said and written about Farmville’s audience of “middle-aged housewives,” our research indicates that it’s not just housewives that are addicted to the game, though users may be more “middle-aged” than for some other apps. When comparing Farmville’s age splits with other top apps, the game has a more substantial percentage of users in the 26 to 35 and the 36 to 45 age ranges than most other titles we examined.

There is one exception — Playdom’s Sorority Life, while popular with the 18 to 25 age group, is also a hit with 26 to 35 year olds, and most of these users, as noted earlier, are women.

Of the games we present here, Crowdstar’s Happy Aquarium and EA’s Restaurant City have the highest percentage of users in the youngest group. 23.1% of Happy Aquarium users ranging from 13 to 17 years old, and 21.3% of Restaurant City’s users are in that range. Both games also have significant distribution in the next age group up, 18 to 15. However, their audiences diminish quickly for the older age groups.

Below are the age group distribution averages across all 18 apps we examined.

From these numbers, we can see that today’s app users on Facebook are as diverse as the site’s overall userbase. These numbers will become even more interesting as we begin to track growth and change over time.

The full demographic breakdown of a selection of 18 top apps on the Facebook platform, including gender and age group splits and growth data when available, is only available through Inside Facebook Gold, our data membership service that also includes the monthly Global Monitor report on Facebook’s traffic growth around the world.

To gain access to the all the data we’re tracking, and to the specific growth projections we’ll soon be adding, please see Inside Facebook Gold at gold.insidenetwork.com/facebook.