Those who use StumbleUpon for both casual web surfing and internet marketing know how powerful the site is. It's grown substantially over the last year or 2, increasing not only it's userbase but also the amount of submitted articles and stumbled posts. One thing that sets StumbleUpon apart from the others is its unique advertising. You can pay $0.05/visitor which StumbleUpon sends your way, and you can do this for any page or article on your site. This adds up after a while - $5.00 for 100 … [Read more...]