I actually know a few site owners who first started out as a small website with a few thousand users and today their sites are worth millions of dollars. We used to talk on a regular basis and once they get so big I never hear from them anymore I am curious to know if they somehow get their site involved in the stock market which finds investors to make their site worth so much even when it offers free service and barely any ads? I used to speak with Justin and Geoff all of the time about new ideas and now I see that StumbleUpon may be worth $50 million: http://www.techcrunch.com/2006/11/14/stumbleupon-may-be-for-sale-50m/ They used to email me and at one point even wanted me to redesign StumbleUpon. I would like to know how these sites are becoming million dollar corporations or how investors find out about them.