Sprint has temporarily replaced mail-in rebates with instant savings, Sprint spokesperson Caroline Semerdjian told CNET this evening. This special promotion will begin on March 27 and continue indefinitely "for an unspecified time."

If the AT&T and T-Mobile merger goes through, then Sprint will be pushed into third place, and will probably need to come up with money-saving solutions like these to stay competitive. It'll be interesting to see if these instant rebates are only a temporary solution or a permanent one.