Spytap in response to Carrier dynamics:
While I think your assessment is probably accurate, I wanted to point something out regarding coverage:
While their CDMA towers, like Verizon’s, cover larger areas than AT&T’s GSM towers, they have significantly fewer of them than Verizon.
The above statement is true, however sprint phones, when away from a sprint tower, roam on verizon’s network without any additional roaming fees. So yes, Sprint has fewer towers overall, however Sprint handsets use other towers transparently as well.
This is true, but there’s a major caveat:
A Sprint phone will hold onto any Sprint signal, no matter how weak, before it will roam onto a Verizon tower.
I found during my month with Sprint in 2007 that I passed through plenty of places where my phone would hold desperately onto the 1-bar Sprint signal, preventing any real use of the phone, even though Verizon had full coverage in the area. In practice, I found very few areas that Verizon covers that Sprint has absolutely no coverage in, so the Verizon roaming was of very limited usefulness.