We've cut down on bag waste considerably here by requiring stores to charge 5 cents a bag. It's amazing how fast people got into bringing reusable bags with them to shop. That said, they still offer you bags, and like you, I'm entirely baffled by many of the circumstances. I'll buy a bag of chips and be asked, "Would you like a bag for that?" For... my bag? You're offering me a bag with which to carry a bag? It's already a bag. WTF? I'll also get offered bags for singular packaged items small enough to put in my pocket. Buy a single-serving bag of M&Ms, and... "Would you like a bag with that?" A bag, for the item I just bought that comes in a bag, that's physically smaller than my hand? Seriously?