Board Thread:General Discussion/@comment-10610378-20130608183359/@comment-6842345-20130613094731

Free to play doesn't mean they aren't going to try and convince you to part with some cash - they do have to pay for all the development time, power, bandwidth and the like. The trick is to find the balance where there is a clear advantage to paying, without encouraging people to leave.

That said, a quote I read a while ago seems appropriate: "if you're not paying for something, you're not the customer; you're the product being sold".