U-Haul's marketing genius

So I bought several boxes from Home Depot the other day. They sell basic 1.5 ft^3 boxes for 97 cents apiece. A good deal, to be sure.

But it turns out 1.5 cubit feet of books is not such a good thing. So I went back to U-Haul, who sells 1 ft^3 boxes (as their "book box" size) for $1.43 apiece. They have an interesting marketing scheme.

It goes like this: buy as many boxes as you want, and if you keep your receipt, you can bring back the extras. Personally, I believe this is pure genius. I have never, I repeat never, had leftover boxes during a move. Everyone has more stuff than they want/expect/can fit into the boxes they bought, so there's always usually some emergency "throwing out" or "garbage bag suitcases" involved near the end of a move. U-Haul is basically removing the element of risk from buying boxes, and so getting people to buy the amount of boxes they really need, and so which they won't be returning. Like I said, genius.