Blogger is an old player in blog-publishing service founded way back in 1998 which was bought by Google in 2003 that was the same year in which WordPress was released and after 3 years came another contender, Tumblr.
All three platforms are widely used throughout the world but looking at the recent statistics it shows that gain of one leads to loss of other.
Have a look at recent statistics comparing usage of each one of them via compete.com :
Top 5 Blogs From Each Platform
NOTE: Only blogs hosted under the root domains are taken in to account.
For example It would count abc.wordpress.com but would not take in to account abc.com even if it is using WordPress.