I saw a tv ad for xfinity and it said you can watch Amazon Prime on xfinity. How does that work without Xfinity charging you?
Streaming apps available in the X1 box (Netflix, YouTube, Pandora, etc.) will count against your internet service's data usage. Also, [speculating here] each provider would have made some agreement with Comcast to be there, which may include an up front payment and/or a cut of the service's subscription fee.
The first time you select something on xfinity that is from Prime you have to link your account. You go to amazon and type in a code from the TV. That device is then linked through xfinity to your prime account so anything you could watch on your computer you can watch through xfinity on your TV
trust me you are paying if you use.
You need to have service from xfinity, which you pay for, and an Amazon Prime account on Amazon, which you also pay for. My new tv lets me choose Netflix, Amazon, Hulu and some other services. I put in the password for my account, and I can watch the show on the TV. They come in on the cable lines maintained by Comcast/xfinity.