This. It's easy to forget that in the beginning, stuff like AOL and CompuServe offered their version of the internet, not "the internet". We've now paved the way for Comcast, Time Warner, ATT, and Verizon to do the same. Look at what the wireless ISPs already do to phones on their network today with locking, proprietary apps (many of which take advantage of zero rating), "free" phones, etc.
Sadly but somewhat hilariously, the thing which might prevent them a bit from offering exclusive-to-their-network content is the fact that in the US, you often don't have a choice of which ISP to go with, so if I really wanted some content which was exclusive to ATT's network, I simply can't switch off of Comcast (apartment building with no other option, past 3 apartment buildings were the same) since they've so successfully monopolized markets.
