Ok, here’s my second theory: They thought, when people look at the price for 8, it establishes how much they think the tans are worth, so that when they look at the price for 3 they will realize how much of a great deal it is. You only get the deal once per customer (I think I can discern that in the small print), so it’s a free promo which has been slightly altered so that people look at it and think, “What the hell?” and it sticks in their head. It also might make people think that it is mistake, and that, therefore, they will be getting a special deal by calling them on it.