this is clearly mentioned on the website Visits not unique visitors The number that Statbrain estimates is visits. It is also known as visitor sessions and indicates the number of visits that a website has. The number is not the same as unique visitors which usually is a bit lower. Visits should not be mixed up with hits or page views which are entirely different numbers.
I compared the results in cpanel stats, I found that gives the number of pages, not the number of visitors http://www.statbrain.com/www.vipublog.com
There's another french site http://pertinence.org where you can estime the number of visits of your site. An example http://pertinence.org/vipublog.com