Of course, it is pretty easy to resell hosting packages for websites with a VPS.
However, you can do lots of things with a VPS that does not include website hosting. You can run applications, programmes, cloud systems, so they would be reachable online. Configure VPS to be a VPN server or a nameserver. You can use VPS just to store your data online or store backups of your data. Also, you can configure VPS to be a game server and many more possibilities.
Aside from websites hosting, you can just store personal files on your own cloud storage with OwnCloud. Having VPS makes it possible to link new domains to it without limiting their number. You can install any programs, modules, and scripts on your virtual private server. You can make a VPN with OpenVPN or a proxy server and use a secure channel for data transmission and bypass blocking of websites. Windows VPS can be used as a remote workstation. You can use VPS for the operation of a media server, for streaming video or for surveillance cameras video storage. It depends only on your purposes.