I believe that it's more of a case of att, tmo and VZ not allowing carlos to advertise that he uses their networks. So it would be of no value for carlos to advertise the other remaining carriers that he has agreements with. Somewhat similar to what Pageplus has going with VZ. They too cannot mention that they use the VZ network.
Originally Posted by CaptainColeslaw
I recently tested the "don't mention a PP Dealer by name" rule here on PP Hofo......trust me, it is still in effect - got me a 7 day ban.