How to select a web content management system? One of the most important criterias is the growth potential. Drupal market share went up 21% last year which is a huge growth:
table showing the usage for the big three CMS providers as well as numbers for the percentage of sites using either no content management system at all or some other CMS (ref)
The abovementioned data is for 2012, before Drupal 8. So growth is expected to be bigger in 2013. Especially in the area of enterprise content management.
Despite the growth, 70% of the sites don't have a CMS at all. And this is where the real growth potential is found. Most businesses still didn't adopt a CMS.