Did you ever fell into the trap that you signed up for an supposedly unlimited service only to find out at a later time that the unlimited service did not really mean unlimited at all ? I fell into that trap with my first website which i hosted using an unlimited webhosting plan. No extra money for transfers over a certain amount of gigabytes, no worries about cpu and sql usage, everything was advertised as being unlimited. I started hosting some file mirros and ran some pretty resource demanding scripts and it did not took long until I was told to either upgrade my hosting account to a dedicated server or leave the company and look for hosting elsewhere.