In hosting business the biggest issue that customers face is overselling the resource by hosting providers. It is surprising that although this act is unethetical and bad for the reputation of the provider, it is one of most common acts provider do. The main issue here is how can the customer detect the over selling before paying the price of the VPS.
Here are some general guidelines will allow the cutomers to eliminate most of overselling providers :
1- Technologies : XEN does not allow over selling of the server resources which is the reason why mostly Xen Providers sell their VPS at higher price tag compared to other technologies. unfortunatly OpenVZ and KVM do allow overselling of RAM and processor.
2- Price : To be accurate this is the easiest way to detect overselling. When comparing too many provider the cutomer can have a feeling of the average price of the VPS. usually providers can be either 30% more or less. When the customers see a VPS price that is less that half of the average price the customer should think twice.
3- Reputation : real good reputation is one of the best factor that Customer can depend on to detect good host. However, this point need more clarification as many hosts post fake reputation to boost their image. So the general rule don’t look for reputation (review) of the host on a a paid review website with few or no comments .