Final answer:
Self-interest in a shop owner can benefit the consumer by providing better or less expensive products and discounts or sales promotions.
Step-by-step explanation:
Self-interest in a shop owner can actually benefit the consumer in several ways. First, when a shop owner aims to maximize their own profits, they are motivated to offer better or less expensive products to attract more customers. This means the consumer gets access to higher quality goods or lower prices. Second, shop owners may provide discounts or sales promotions to incentivize consumers to make purchases, further benefiting them. Therefore, the shop owner's self-interest aligns with consumer satisfaction in terms of product quality and affordability.