How's this for an instant discount? Beginning Wednesday, when you trade in (almost) any old smartphone, AT&T is knocking $100 off the price of any new smartphone -- including the , , , and .
Of course there are a few caveats. Smartphones can't be older than three years, and need to be in good working order. As a bonus, though, AT&T rates some trade-in phones at more than $100, which means you could get even more off that asking price.
The offer extends to AT&T retail stores as well as authorized distributors, and the $100 credit is instant.