Some vending machines are too heavy to carry without special equipment and/or helpers, especially if the machine has to go up or down stairs. As with bulk vending, turnover of accounts (in the event of a store closure or relocation, for instance) requires a repeat of the process of finding a location and moving the machine. Snacks and soda also have lower gross margins than bulk candy. Attention must be paid to the expiration dates on potato chips, sodas, and other products.