For sure social networking sites are dominating the web. Like other social networking sites, Tumblr is another form of blogging or micro-blogging platform with easy-to-use features.
Tumblr themes are easy to create and customize and one can follow with other users and be followed back as it offers media outlets to interact with followers. With user numbers and popularity on the rise, Tumblr received over 6.6 billion page views per month and with the total average, Tumblr visitors are spending 1.5 hours per month. It provides a smooth platform where you can share anything such as text posts, quotes, photos, links, music, and videos like other social networking sites and getting more than 93 percent of its revenues via ads, social media pages, and brand posts.
Tumblr is having 90 million of users that generate more than 89 million new posts every day. In fact 50 percent of active users access Tumblr through their mobile apps and tablets.
For more details here is an infographic by the team of Websitehostreview.com which punches some idea of How Big is Tumblr. 
