Facebook board member, Silicon Valley entrepreneur and web browser pioneer Marc Andreessen says that social networking site Facebook will earn over $500m (£310m), and will make many billions of dollars in revenue in five years.
He told Reuters: "This calendar year they'll do over $500m. 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 is starting his own venture capital fund with Netscape executive Ben Horowitz, and now regrets not investing in Facebook: "I probably could have if I had tried hard but I didn't".
Andreessen did invest in micro-blogging site and Facebook competitor Twitter.
Speaking to Reuters Andreessen even claimed that Facebook could earn more than a billion dollars this year if it pushed harder on selling advertising.
However, he said that that it was more important at this stage for social sites like Facebook and Twitter to retain and grow their user base and capture market share, rather than worry too much about making lots of money right away.
Horowitz pointed to the once-dominant social network MySpace, now owned by Rupert Murdoch's News Corporation. He believes that MySpace focused too much on selling advertisements and not enough on developing the platform: "If the revenue degraded the user experience then that was a very dangerous thing to do," Horowitz said.
Andreessen devised the Mosaic web browser, which is still influential in the code of most of today's commercial browsers. He founded Netscape and also most recently the topic-oriented social network Ning.