That's actually kinda disappointing. I'd always assumed those flyers were pieces of trash (at best, something I'd need to put in a recycling bin) which I don't want but now I'll be more tempted to take them when offered on the chance that I otherwise accidentally avoid the sales price.
It's still good to know that such coupons are likely just attempts by the retailer to circumvent the manufacturer's... ahem suggested price.
Since none of their lumber should ever be in the same building as the word "straight", I made a joke to a nearby employee that we should get a discount at how warped the wood was. He very seriously told me to separate the warped wood on my cart, and he'd mark them down. Got to the register, and they were marked down 40%.
Second instance was after spending time chatting with an employee in the appliances department, he pulled out a pre-printed, handcut piece of paper from his apron pocket, wrote 10% on it with his sharpie, and i got 10% off at the register.
Oh, and of course the Guitar Center stories of "you're a cool dude, and since I like you, let me knock of X%" are infamous
So the item price matches Amazon's, but you pay less in the end, if you're even remotely paying attention.
At least for the $200-300 items I've seen (like dehumidifiers, fancy computer accessories).