Inside Facebook

Entrepreneur Marc Andreessen, who sits on Facebook’s board of directors, said in an interview today with Reuters that Facebook will see $500 million in revenues in 2009. He also said he expects Facebook will be doing “billions in revenues” in 5 years, and employees who sell their shares now are “making a mistake.”

Speaking on the same day that his new VC firm, Andreessen Horowitz, was announced, Andreessen said that Facebook could be making much more money than it is today if it wanted to.

“If they pushed the throttle forward on monetization they would be doing more than a billion this year…There’s every reason to expect in my view that the thing can be doing billions in revenue five years from now,” Andreessen said.

These numbers correlate with estimates we’ve been hearing in recent months, but it’s the first time someone from Facebook has spoken publicly in absolute terms on revenue figures for 2009.

A source estimated Facebook’s 2009 revenues break down this way, according to Silicon Alley Insider:

• $125 million from brand ads
• $150 million from Facebook’s ad deal with Microsoft
• $75 million from virtual goods
• $200 million from self-service ads.

Last month, when Facebook announced its $200 million investment from Yuri Milner and Digital Sky Technologies for 1.96% of the company in the form of preferred stock (in which DST did not get a board seat), Facebook and DST also announced plans for DST to buy “at least” $100 million of Facebook employee shares. That plan hasn’t taken effect yet, but Andreessen is advising employees against cashing out now.

“Generally speaking, people who are selling their stock in Facebook now are making a mistake,” Andreessen said.

Facebook of course hasn’t announced any plans for an IPO yet.