Been searching for that new tablet on Google lately? If so, Google may recommend, via Google Now, when you are near a store that carries it. They will even conveniently tell you the price. In one sense, this is the oldest rule of retail: the impulse purchase. High margin impulse purchase items with high turnover are kept near the front of the store, tempting you to snag that candy bar or soft drink you’ve been thinking about since you saw it on the way in.