Probably because of boost offering of unlimited 4g, tmob and metro has to do something in response...but sprint has the massive wimax network and can go deeper with capacity offering, so sprint can price out tmob and metro to capacity submission
Yes, and you could use facetime easily on s/clear's 4G wimax-unlike AT&T.
"Beyond the net neutrality issues, AT&T is concerned with the impact a data-intensive app like FaceTime will have on network performance and customers' wallets. For several years after the release of the first iPhone in 2007, AT&T struggled to accommodate the huge increase in data traffic. The poor performance of its network in some major cities made the carrier the butt of jokes from comedians on national TV, as well as ridicule from customers."