That is too generally, most of companies allow a free usage, because they want to convince about their service and set the hurdle of usage as low as possible.

That is too generally, most of companies allow a free usage, because they want to convince about their service and set the hurdle of usage as low as possible. Companies like google, yahoo, facebook, ... are a different kind of "free" web-service. Or free 2 play games, free players are "content" in that games.