Free web hosting to the extreme!

I just wonder how all these free hosting providers pay their hosting bills. Except the hosting people with ads, i think no body can survive in the long run. But it seems there are hosting people who can survive this.

For example, take a look at the offers being made by free hosting company's at free hosting world. They seems to be crazy. If one offers 1gb space a nd 20gb bandwidth with no ads(ooblez), the other offers 5gb and 65 gb with ads(cybertoad). There is an offer from i6networks with 5gb space and an incredible 1terra bytes bandwidth hosting!

I really hope all of them stay in business.