The LA Times has a detailed analysis up on the subject of MVNOs (Mobile Virtual Network Operators). These are small wireless carriers like Helio, Amp'd Mobile, Virgin Mobile, Disney, and the now-defunct Mobile ESPN, which returned as a Verizon V CAST premium channel. MVNOs license network bandwidth from big carriers like Verizon and Sprint, but offer their own packages of special handsets, plans, and mobile media channels.

The articles contrasts the failure of Amp'd Mobile with the success of Virgin Mobile, another youth-focused carrier that is adding subscribers at a pretty good clip: "Amp'd stuck with the youth market until the end despite young customers' unwillingness to pay their bills, while Virgin's use of prepaid plans caught on not only with youngsters but also with older folks."

Amp'd bragged about getting $100 from each customer per month due to its comprehensive (and expensive) TV and video channels. The end result was that many Amp'd customers signed up even if they couldn't afford it. Then they just didn't pay their bills.

Amp'd closing shop even as rival Virgin Mobile thrives [LA Times, reg req'd]