StumbleUpon

StumbleUpon is described as a discovery engine that finds sites and makes recommendations of sites and content based on users personalized input and tastes. StumbleUpon has been around since 2002. In September 2012, StumbleUpon released an update for its iOS app that brought the new feature "StumbleDNA," which aggregates content that is recommended for you, trending content as well as a section where you can view the activity of your StumbleUpon connections. Its has a toolbar available for all the major browsers (Google, Internet Explorer, Firefox, Safari and Opera), as well as, mobile app access on Windows phones, Android phones, i-phones and Amazon Appstore.

Rating Web sites update a personal profile and generate peer networks of Web surfers linked by common interest. These social networks coordinate the distribution of Web content, so that users "stumble upon" pages explicitly recommended by friends and peers. Giving a site a thumbs up results in the site being placed under the user's "favorites". Furthermore, users have the ability to stumble their personal interests like "History" or "Games". The social content discovery approach automates the "word-of-mouth" referral of peer-approved Web sites and simplifies Web navigation.

Paid Discovery is StumbleUpon’s ad system. StumbleUpon’s platform lets users surf the web by Stumbling to sites that match their interests, simply by hitting a button on their browser or mobile device. With Paid Discovery, an advertiser’s URL (website, video, etc.) becomes part of that stream. Up to 5% of all stumbles are reserved for Paid Discovery where the advertisers directly insert their web page into the user experience. This means the audience lands directly on their web pages, videos, and photos. Users can also provide feedback (thumbs up / thumbs down) on this content. Since Paid Discovery sends visitors directly to the advertiser’s page, there’s no need to create an ad; the advertiser’s entire web page is the ad. When an ad is delivered a user, a green icon or “Sponsored” will appear in the toolbar or mobile app, denoting a paid stumble. StumbleUpon doesn’t serve typical display ad formats, such as pop-ups/interstitials, banners, etc.

I can see this as a great tool for companies wanting to market via the web or social media and since its peer to peer based in nature, when one person lands on and then thumbs up an advertiser's page, their peers will have those sites recommended too. Its another tool in the belt in addition to Facebook or Twitter or any other social media site. For users its like what Kayak is to travel sites, but for their personal interests.