Observe the difference in vending machines between canned soda and newspapers. Typically, if you insert coins into a newspaper vending machine and open it you will see available all of the copies of the newspaper within one's reach

However, soda machines are very different. They work such that only one can is dispensed at a time. The rest of the canned soda is well out of reach. Explain in terms of marginal utility why the newspaper distributor is relatively unconcerned about the rest of the newspapers being taken without payment while the soda distributor uses a machine that goes to great lengths to insure that only one can of soda is dispensed at a time.

The answer is fairly straightforward. A second or third newspaper probably has close to a zero marginal utility for the typical consumer. The second copy doesn't really provide him with any net gain in satisfaction. However, the rest of the canned soda in all likelihood would still have a positive marginal utility for most consumers. Therefore, it is worth it to spend a little extra money on a machine that keeps the rest of the product away from prying hands. By contrast, the low incidence of theft of newspapers provides no justification for a more complex vending machine.