WP Frog put together an illustrated look at how many sites use Word Press and the most popular plug ins.
Since WordPress was born, 9 years ago, and until now, in 2012, its
users reached more than 11 million.
Some of the most used plugins for WordPress are All in One Seo Pack
(with more than 9 million downloads), Google XML sitemaps (with almost 7
million downloads) and Contact Form 7 (with more than 5 million
downloads). Currently, around 22% from new websites are running on a