From what I've read (very little) it sounds like they use other carrier's networks. I've also read conflicting reports that their "unlimited data" isn't truly unlimited. Some say they cap you at 5gb and could even possibly terminate your data beyond that. Others say you can't download/upload video and audio (i.e. no netflix, youtube, pandora, google music, etc.). I'm not sure what to believe? The positive is that their network is pretty extensive and covers most of the us. No 4G at this time, but 3G should be sufficient unless you're coming from Verizon LTE. There's a lot of speculation that this won't last long. I'll keep an eye on it to see if it's a viable option when my contract is up with Big Red.