What is overselling enabled?
Overselling enabled is where we take the amount of disk space and bandwidth ACTUAL USE between all your accounts. For example, if you had the 10 GB space and 200 GB transfer plan and you decided to offer plans such as 1 GB space and 20 GB transfer on your site, you would only be able to offer it to 10 clients. With overselling enabled, you would be able to offer as many as you want as long as the aggregated amount USED between all your accounts does not go over the 10 GB space and 200 GB transfer or the cPanel account limits.