We had our sites hosted with another company and were pay a monthly fee but were limited by the number of domains and sub-domains that we could use.
We use a lot of sub-domains in our business so we started looking around for a hosting plan that was unlimited, thats when we found HostPapa.
We took out a 3 year plan that allows us unlimited domains, sub-domains and email addresses, all for what is used to cost us for 1 yr with our previous hosting companies limited account.
We have now been with HostPapa for over 12 months and have no plans to change. The unlimited account is great and there has not been any time when the service has been down.