StumbleUpon The Antithesis of Google? With over 3.5 million registered users (up from 600,000 two years ago), StumbleUpon has left the techie niche and has become mainstream. But unlike Google which makes its billions from helping you find what you're looking for, StumbleUpon helps you discover content that you may not be looking for but will probably find interesting. in Articleswith articleblog-postbusiness-modelgooglestumbleuponweb