Tumblr

As a social network based on the microblogging format, Tumblr allows registered users to post both text, images and other multimedia content. This short-form blog was the creation of Kavid Karp, with the help of Marco Arment as lead developer and was launched in April 2007. Within five years it reported 77 million blogs with over 13 million unique visitors from the United States.

In June of 2012 released Tumblr 3.0, which is a version of its iOS app, but now supports Spotify, offline access and high resolution images. During this time, Adidas became its first major brand to launch an advertising campaign that featured a soccer blog. The company also bought ad placements that were displayed on the user dashboard.

The service is most popular with the teen and college-aged user segments with half of Tumblr’s visitor base being under the age of 25. Some famous Tumblr users include John Mayer, Lady Gaga and Zooey Deschanel. And in 2011, the Occupy Wall Street movement created the first unifying social network slogan, “We Are The 99%.”