Tumblr has hit a major milestone — 20 billion posts — a huge increase from the 12 billion posts figure it reached in November.

"Forgot to make a big deal of this earlier, but Tumblr crossed the 20-billion-post mark Monday night," said a tweet from the official Tumblr account, with a link to Tumblr's About page, which sports a counter showing the total number of Tumblr posts.

Currently, the number sits at more than 20 billion posts, 51 million of which were created today. Tumblr currently has more than 49.7 million total blogs and is due to hit the 50 million milestone any day now.

The rapid rise of Tumblr in the past year has been nothing short of amazing. In June 2011, Tumblr announced it had more blogs than WordPress.com — more than 20 million. It took less than nine months for Tumblr to double that number.

For comparison, WordPress powers more than 72 million blogs, about half of which are hosted on WordPress.com.

SEE ALSO: Tumblr Hits 15 Billion Monthly Pageviews

The simplicity and ease of use of Tumblr on one hand and similarity to microblogging services such as Twitter on the other, have apparently hit the right spot with a large number of users. One thing Tumblr still lacks is a viable business plan — despite significant funding.

BONUS: 25 Outstanding Kitty-Themed Tumblrs [LOTS OF CATS]

What would Tumblr be without the occasional cat post?