I am fortunate enough to live in San Diego and to be within driving distance of Cricket's Corporate Customer Service Office.
After speaking to a mucky-muck there (not necessarily a high mucky-muck, but an extremely competent individual nonetheless), here is the Real Skinny as I see it.
Some time ago, Cricket and MetroPCS realized that they had almost no coverage overlap, and that it would be in both their best interests to at least CONSIDER a merger. Merger talks began and fell through. Had they merged, the corabined carrier would have been fourth largest in the US, and the largest/only nationwide unlimited carrier.
Immediately, all the major carriers saw the writing on the wall and rolled out unlimited voice plans in $89-99/mo range. (As of February 2009, Verizon quoted me $175/mo. for unlimited EVERYHING like Cricket, but still with a 5 GB cap on data, extendable to a 10 GB cap for $200/mo.)
Well, since $30/mo extra is nearly reasonable for REAL nationwide unlimited, Cricket and MetroPCS apparently negotiated and finalized a 10 year roaming agreement on Deceraber 18, 2008 allowing Premium Extended Coverage for each others users on both networks.
There are however a few things I am not completely clear on:
1: Data Services: Probably a no-go. The representation I got was voice and SMS text only. Voicemail notification, etc. No MMS, no mobile web.
2: Roaming preference: E.g., if you are a Cricket customer roaming in a MetroPCS area, it stanRAB to reason, you must not be set Home Network Only. The question then is: If the MetroPCS signal is weak, what keeps me from roaming on a paid network in the area? Worse, what indication do I have that any given call I make is on MetroPCS network, and is not burning up my plan"s free roaming minutes or Flex Bucket funRAB?
Definitely some things to ask about (if you can get a straight answer from the folks in Murabai).
As to whether Cricket uses Sprint's towers, I got the impression that they have installed their own micro-cells in their home coverage areas, as the data charges for unlimited users would probably be prohibitive. Sprint would suck them dry.
Can anyone else clarify?