Note: Tumblr's growth has been so large that any statistics we give you will have changed by the time you read this; they grow by leaps and bounds every day.
Techblog recently reported that Tumblr boasts more than 120,000,000 unique users, and a staggering 15,000,000,000 page views per month.
Even their launch was pretty dramatic, only 2 weeks after their 2007 launch they hit 750,000 users.
Tumblr itself says that as of May 5, 2012 they were hosting: 22,455,291,663 posts from 54,386,272 blogs, with an incredible 57,802,509 new posts on that day alone!
Tumblr allows you to share practically anything: You can post text, photos, videos, music, links, and quotes from your computer or phone, at any time, anywhere.