It is cheaper - I'm saving $1000 bucks on my iPhone over the course of two years, just by buying it unlocked and on a cheaper plan. I can use it in other countries as well, just a matter of swapping the SIM card. Only downside is that my network provider won't replace my phone if something were to happen to it, but I'd imagine there are third party insurance providers in this space.

I think there are a few reasons why companies like Verizon are so big in the U.S.: they have a good network, they offer plenty of family plans, and they will replace your phone for what seems like subsidized rate under various conditions. Oh, and they advertise constantly.

But not being able to use my phone out of the country? Very limiting. Why would I pay more for that handicap as an individual enrollee?