The social bookmarking/discovery engine StumbleUpon announced yesterday on a new milestone- 20 Million members (Stumblers)! The site released a nice image (see at the bottom) describing the company’s history stats to celebrate the event.

Back in August, i have reported that StumbleUpon is on the rise and gaining big momentum in 2011. The stats released by the company confirms what i reported:

–  The total number of users has been doubled in 2011- From 10 million to 20 million.
–  The total number of employees has been more than doubled in 2011- From 40 to more than 80.
–  The monthly Stumbles (posts) has grown by more than 2.5 times- From 400 million to more than a billion.

Although StumbleUpon is often drowned in the social networking mix that is ruled mostly by social networks like Facebook, Twitter and now also Google+, The site has become a social force to reckon with and should definitely considered on the marketing efforts.

Let’s overview the company’s major milestones (taken from the stats image):

February 2002- StumbleUpon launched as a Firefox add-on.

Late 2004- Celebrating 100,000 members.

July 2006- Celebrating 1 million members.

May 2007- StumbleUpon Acquired for $75 million by eBay.

April 2008- Celebrating 5 million members.

April 2009- The founders and several more investors acquiring back StumbleUpon.

May 2010- Celebrating 10 million members.

August 2010- Launching its first mobile app.

October 2011- Celebrating 20 million members.

Here’s the StumbleUpon’s history image with full stats: