Why is toothpaste almost always free or nearly free?

That's cool and all, but I'd like to see more rotation out there. People covering stores like Walgreens... it's all the same items all the time. Mostly P&G, some Unilever, and Colgate, and if not Colgate, then Crest. I don't resell, there is only so much want I have for toothpaste. And sometimes I have soon expiring store money (wags cash/RR/ECBs/etc) and just want to roll it.