Is an unlimited account actually unlimited?
The answer is yes.... but within reason.

While we advertise an unlimited service we do need to be realistic. We will support your project up to the point where it negatively impacts on other users. We have ways to stop one hosting account affecting another such as limiting the overall memory that can be used and I/O limits etc.

Put simply, for most business and personal hosting projects this service will work excellently, but don't expect to be able to run Amazon from our servers they are just not that powerful.