Tried this twice over the weekend, Friday and Saturday night. Ended up with free stuff both the next days.
Ok the first day it was just a free bag of dog food - but still - saved me 25 bucks
And the second day I got a gift certificate for a restaurant for spending a certain amount at a store. The cashier actually gave me 2, because I spend double the amount required. Said she "wasn't supposed to" - but did it anyways - I didn't even ask her to!
still waiting for todays surprise ...