I am wondering why GoDaddy offers "Unlimited Space+ and Bandwidth", but Google app engine/AWS charges on usage. Is it REALLY unlimited? If GoDaddy offers lower rate, why do people still use Google app engine and AWS (other than they can use more customized virtual instance).
Can anyone explain it to me?
They don't actually offer you "unlimited" anything. It is a gimmick, and they are betting on average, their users would not exceed a particular threshold.
I bet if you tried to upload 10TB of data on an unlimited plan, not only would you run into physical storage barriers, but your account would probably be terminated for insert random reason here.
"Unlimited" word is used by so many hostings, today. Actually, knowing the limits, and the reality behind it, is not terrible to get into a server that claims it can offer that (it is more important to know what the people say about it, the time it's been working, etc, etc). Just be sure that if your bandwidth usage would be really high, often using some script, forum, multiplayer game, etc, which could make cpu share usage higher (rarely if you have just static pages) than what is usually allowed in a shared hosting TOS, your account would get probably suspended.
These days I can think of a few good and reliable hostings that use that gimmick in their offers. The other thing you mention, AWS, cloud, etc..Gives you a special flexibility that you cannot find in traditional hosting. It depends on each case, plans, etc.
This may answer your question: Do web hosts really mean 'Unlimited'?
Terms and conditions of different web hosting services allow for different storage spaces. Some will charge you when you exceed a certain limit. In fact, they aren't even required to disclose the limit you have on some web hosting services.
No hosting service is 100% free - there is always a lurking payment at some extent. Always read the terms and conditions first.
