Spint lost 1 million customers in the first quarter of 2008, while other major carriers grew. I've been a Sprint customer over 10+ years and several of my friends also have Sprint, and I have to say this doesn't really surprise me. For me the problem with Sprint comes down to one thing: lousy phones. Sprint consistently has the lamest selection of handsets of any cell carrier out there, and I think it's finally catching up with them (thanks, in no small part, to the popularity of the iPhone).
Sprint is often behind the curve when it comes to offering the latest and greatest handsets. Sprint was among the last carriers to get Motorola's line of popular MOTO phones. Sprint added the RAZR to it's line-up in late 2006 about 2 years after every other carrier had it (and most customers had gotten bored of it). Sprint was also slow to offer Blackberry handsets, although now it seems to have mostly caught up. Phones from brands like Nokia and Sony rarely come to Sprint, and the brands Sprint carries don't exactly carry the same level name recognition and status. Looking through Sprint's line-up I see a lot of very basic, somewhat outdated looking clamshells, and overall many fewer options than companies like AT&T. Sprint has gotten slightly better recently with having short term exclusivity on cool phones like the Palm Centro, and HTC Touch, but it's still probably not enough. Sprint is also looking to challenge the iPhone with the new Samsung Instinct, and has even released side-by-side video comparisons of the two phones. But unfortunately Sprint's timing couldn't be worse, as Apple is rumored to release a 3G version of the iPhone with GPS in about a month. Also, no amount of money Sprint could spend pushing the Instinct could even begin to rival the amount of advertising and free promotion the iPhone commands.
What's interesting to me about is how Sprint has been disadvantaged by being a first-mover. Sprint was the first company to offer digital cell service back in the 1990s. At the time Sprint's CDMA network offered features and call quality that the competing analog networks couldn't touch. Back then CDMA networks were a bit more proven then the competing GSM standard and it seemed like a safe bet. However, GSM networks quickly caught up and became much more popular globally. Now GSM networks have about an 80% market share. Consequently, the number of CMDA compatible handsets became limited. It's really disappointing to see a pioneer of digital cell service fall behind. And I have to say, part of the reason I've stayed with Sprint so long is because of its heritage. But since getting my current phone, a MOTOSLVR, I've had it with second rate hardware and I don't plan to renew my contract with Sprint. Also, the iPod touch has really wet my appetite for an iPhone.