Sure, if you've had that never-goes-on-sale jacket in your cart for eight months, why not take advantage of an extra 15 percent off? You just afforded yourself two fancy lunches this week. But wait, that save $10 off a $50 purchase coupon shouldn't be a reason to buy a bunch of stuff you never wanted (until 20 minutes ago). Better sales come, and 15 percent is chump change in the bargain shopper's world. Still, we don't recommend any impulse buys, but if they do happen it better be a great deal (or something actually awesome). Use these small sales to buy things you would have purchased anyways.