We've received them for doing a change of address at the post office. We have also received them in the past for signing up for Lowe's newsletter. But that was years ago and not everone who signs up gets them. Or at least that's how it seems as we have friends who've signed up an never received them.
I do know that occassionally Home Depot has random days where all purchases are 10% off. They usually seem to near holidays but every now and then they are just random. You usually ahve to ask for the coupon if no one is handing them out. HTH.