CentOS is one of the most popular Linux distributions in the hosting industry. Due to CentOS’ binary compatibility with RHEL, it is highly compatible with most Linux software. Most hosting control panels use CentOS as the preferred Linux distribution.
CentOS exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream source, Red Hat.
In July 2010 CentOS overtook Debian to become the most popular Linux distribution for web servers, with almost 30% of all Linux web servers using it. But in January 2012, it lost that position to Debian once again
A major factor that might influence web hosting clients to choose CentOS is web hosting control panel compatibility. Within the web hosting industry, CentOS dominates, and most web hosting control panels, including InterWorx and cPanel, focus on RHEL derivatives like CentOS. If you plan to offer web hosting services using a control panel, then CentOS is probably your best bet.