Sprint paid over 20 billion dollars for access to new iPhones through 2015. As part of that deal, they have agreed to buy 30.5 million iPhones from Apple, regardless of whether or not they are able to sell them, which works out to Sprint subsidizing each handset by $500.
That is quite an investment on the part of Sprint. My gut tells me this will not work out for Sprint and will ultimately bring about their demise. And no, I am not an iPhone hater...I think it's an excellent product for most people. I just think Sprint overpaid so they can get in on the iPhone "money-train". I assume AT&T and Verizon will continue to carry the iPhone so that's some stiff competition and Sprint's overzealous buy-in may end up being rash.