How can companies like blue host or 1and1 sell hosting packages that have 10gb and 100gb transfer etc at shared hosting prices -.- really cheap... how do they keep the money going??? Why would someone need that much! wouldn't they need more cpu and ram than a shared server can provide?
This topic has been talked about a lot. They are playing the odds that most people will never come close to using that much space and bandwidth.
If you do a search for something like "extreme overselling" you will find many threads about this.
Ya hosting is moving to just using those as marketing tools, the real limits now are CPU/MEM and limiting the use of your customers to those resources.. maybe the next really great product is like a mini VPS setup where you can limit 100 shared customers to not killing the server with runaway or loopking cgi/php or mysql calls...