Given its simple, concise nature, Tumblr is not best suited for long text-based posts like full articles; rather, it's good for broadcasting short messages to readers. The microblogging platform is praised for its simplicity in aesthetics, management and content posting. Many Tumblr blogs feature humor, fashion, design and art.
Each Tumblr blog is referred to as a tumblelog. Members can post text, images, videos, links and audio files to their tumblelogs. They can personalize their tumblelogs with different themes, which are largely free but can be professionally designed for a price. Primary tumblelogs are public and cannot be password protected, but specific posts can be made private. One account can host multiple tumblelogs.
A popular tool is the "re-blog" button. Users can click on a post they like and it will be published to their own Tumblr for followers to see. Tumblr limits users to 250 daily posts to control bandwidth use and spamming. There are Internet petitions asking Tumblr to terminate the posting limit because, some users say, their freedom of speech is being oppressed.
More than 50% of Tumblr visitors are under the age of 35. The retention rate of users is twice that of Twitter. Tumblr was founded by David Karp in February 2007. According to Tumblr, as of July 2012, the platform boasts more than 70 million blogs, 30 billion posts and 16 billion monthly page views.