i think at least a lot of things (if not most things) that i pay for have an agreed-upon result in exchange for payment, and a mitigation system that'll help me get what i paid for in the event that something else prevents that from happening. if you pay for something and you don't know what you're going to get, and you have to keep paying for it in the hopes that you get what you want out of it... that sounds a lot like gambling. not exactly, but like.
If I ask an artist to draw a picture, I still have to pay for the service, even if I am unhappy without the result.