In the web hosting world, overselling means advertising benefits which a client pays for, but cannot really take advantage of. Many of the features of a given web hosting plan can belong to this category - hard disk space, traffic, database storage space, etc. A plan may come with unlimited disk space, as an illustration, but many hosting providers make accounts on just a single server that can have only so many hard disks and since all the customers upload content, there will be no space left on the server at some point or there will be some hidden quotas so as to ensure that each and every user has their share, even though everybody has paid for limitless space. As most hosting Control Panels are designed to work on one server, a number of providers don't really have a choice but to oversell, that's nothing else but tricking their clients.