It works badly. If you want any kind of post-paid plan you typically are forced to purchase a phone with a carrier lock. Some pre-paid plans will let you purchase SIMs and "bring your own phone" (Wal-Mart's "Straight Talk" being the largest that I'm aware of-- they're an AT&T MVNO).

The average US cell phone user has no idea that phones and service aren't one-in-the-same.

Last weekend I went to an AT&T store and got a 'post-paid plan'. I just asked for a SIM and they gave it to me. No one forced me to purchase a carrier locked phone.

I studied one semester as an exchange student in the US, and it seems like everyone there is attached to a plan, prepaid contracts are not popular, actually they aren't a good deal. I got a prepaid simcard and it was really expensive they even charged me .25 dlls per every received text, I'm not sure if every company is that expensive, but I guess they are.

yes, they are. oh, and sending would cost you .25 as well, unless, of course, you purchase 'unlimited' texts for $20/month, then, you see, they're 'free'. texting is insane and I have to remind people not to text me on a regular basis.