Can you use an At&t, Verizon, or Sprint iphone 4s on Virgin Mobile?

$549.99 seems like a lot for an iphone 4s, and i can find cheaper ones on craigslist. So do you need to have the actual iphone 4s (for virgin mobile) to use their service?

No, Sprint and Verizon use CDMA, and AT&T uses GSM. Virgin runs on Sprint's network (CDMA). Even if you have a sprint iPhone I'm pretty sure Virgin makes you use the Virgin mobile iPhone.

You would need to buy the one from Virgin Mobile. That is their rules.

Yes and no?

Sprint and Verizon uses a standard known as CDMA (which only America uses now), and AT&T uses GSM (which is worldwide (more or less) compatible). Virgin is also on CDMA.

If you have a sprint or Verizon one, yes, otherwise no. All that will happen is you get a 'SIM chip' from Virgin and put that into the phone and it'll work. Since the only thing that keeps you from getting onto someone's network are two things:

1) Compatible handshake (in the form of the SIM chip you put in your phone, or jail-breaking to mimic a similar signal)

2) Compatible radio inside the phone (CDMA or GSM)