Credit card? For what? I thought that once the box was purchased and hooked up I was in the clear. Is there a monthly subscription fee?
To pay for fees or subscription services to services like NETFLIX.
It is a sales strategy. They get your CC number so that IF you decide to PAY for a movie, there is no wait. You may think you will never PAY for a movie, but that is not the point (from their point of view). Their point is that IF they have your CC ready to go, it will ENCOURAGE you to PAY for a movie because you don't even (then) have to think about it, or go find your CC and enter the information and wait for a confirmation , and ... whatever else would keep them from getting your movie to you quickly and MAKING A 'SALE'.
I know this because I bought a ROKU and couldn't get it to work without a CC. It says in the instructions that you MUST have a Credit Card. It also 'advertises' that you can use PAYPAL set up with your bank account instead of CC but if you try, PAYPAL then asks you for a CC (the old Catch-22).