StumbleUpon, the social bookmarking site that was acquired by eBay, has hit 7 million users according to Garrett Camp. StumbleUpon requires the use of a web-based or browser add-on toolbar.
If you like a website, then you simply click the “I like it” button. You can discover new websites based on your interests by pressing “Stumble!” on the toolbar.
When clicking “Stumble!”, the website that is pulled up next is based on both interests and the ratings by your friends. The ratings of people with similar interests also have a role in displaying websites.
Although the toolbar has been created for Firefox and Internet Explorer so far, third parties have put together a StumbleUpon toolbar for Opera and Safari.
Garrett Camp, Geoff Smith, Justin LaFrance, and Eric Boyd created StumbleUpon when they were in post-graduate school in Calgary, Alberta, Canada.
“When we passed the half a million mark (in registered users), it seemed more real,” stated Garrett in an interview with the BBC a few years ago. Clearly, StumbleUpon is growing like a weed because they have 14 times the amount of users from when Garrett said that.
StumbleUpon became popular among the Silicon Valley crowd quickly. This is what led to a $1.2 million investment in the social bookmarking site by Brad O’Neill, Ram Shriram (Google), Mitch Kapor (Mozilla Foundation), Josh Kopelman, and Ron Conway. O’Neill also helped Garrett Camp and Geoff Smith transition in moving to San Francisco.
In December 2006, StumbleUpon launched StumbleVideo. StumbleVideo allowed users to click Stumble! and just have videos show up. The site includes videos from YouTube, Google Video, MetaCafe, MySpace, and CollegeHumor. About a year later StumbleVideo became compatible for the Nintendo Wii.
Around April 2007, StumbleThru was launched. This enabled users to Stumble! through different pages of specific sites. For example, if you were visiting a result on Wikipedia, then a Wikipedia button would show up on the toolbar. Clicking that button would use the algorithm to stumble you to another Wikipedia page that you might be interested in.
In July 2006, StumbleUpon had about 1 million users. Around May 2008, StumbleUpon had seen its five-billionth stumble. About one billion stumbles happened in 2008 alone. eBay bought StumbleUpon in May 2007 for about $75 million.