Verizon (cable specifically) already sells "adult content" in the form of premium channels, like most cable providers in the U.S. In fact they have defended carrying of such channels by saying consumers want the choice. While they don't produce it, they are certainly making money off of it and defending the choice to do so.
Well, there's "adult content" and then there's porn. The stuff on cable channels is pretty much "soft core" which stops just short of a certain line. I guess that's how they can defend it.