A couple of weeks ago, I listed 23 types of social media sites and mentioned that StumbleUpon defied definition. It’s not your typical social bookmarking site. StumbleUpon is a unique site that is part social-networking community and part personalized recommendation engine and allows users to “channel surf” the web. “Stumblers” set preferences to discover online content, and then give returned sites a thumbs up or thumbs down, which tightens one’s personal search parameters.
The more you stumble and vote, the more attuned to your likes and dislikes StumbleUpon will become. And the same goes for your target audience. This means that StumbleUpon actually delivers niche-targeted traffic to your site. And, that traffic isn’t just niche-targeted, these visitors are actively seeking certain content topics. Pretty cool.
Besides being a great place to discover great content and market your own stuff, StumbleUpon is fun. Here’s how it works:



