The two-year phone contract is almost dead. According to The Wall Street Journal, Sprint plans to stop offering contract phone plans by the end of 2015, focusing instead on off-contract, monthly plans. Sprint is the last of the major four carriers to start making major moves in this direction: T-Mobile first stopped selling contract plans two years ago, and Verizon joined it this month; AT&T still sells contract phone plans, but they're harder to get than they used to be — you have to buy them through AT&T itself, not through a retailer like Best Buy.
Like its competitors, Sprint has been slowly shifting away from contracts and over to smartphone payment plans. Payment plans — which break up the cost of a smartphone across monthly payments — allow carriers to keep customers on something resembling a two-year contract while still presenting them with lower service prices and the ability to cancel service and change plans when they want to. It's apparently a winning formula, as every major carrier is now making the switch. AT&T may not be all the way there yet, but at this point, it's only a matter of time.