don't put it on your kid's computer like my wife did. Impossible to remove/cancell. If you try to do it by phone they tell you to do it by web, end of story. I went through the first line and the supervisor at their customer support and they could not/would not cancel my account. It's their BOD that sets the barriers so high you give up. Ethically rotten.
I use iTunes as it's the best -- and I've tried them all. But I've never bought anything from the store.