Not really sure. I know TMS is on commission, but it's very minimal. Not sure about WoW mobile, probably commission too.
That being said, from what I remember they were paid based on activations and that is all. If a customer were to return the item, then the commission would be refunded. Canceling it but paying it out wouldn't because it had nothing to do with the actual retail store. Things may have changed from a while back though so I'm not sure how it is now.