Final answer:
Tied selling is when a customer must buy a secondary product to purchase the desired one, which can limit consumer choice and be deemed controversial. Unlike bundling, which often benefits the consumer with better prices, tied selling can be disadvantageous and is seen as potentially anti-competitive.
Step-by-step explanation:
Tied selling is a practice in which a customer is required to buy one product only if they also purchase a second, often related, product. This practice is controversial because it can force consumers to purchase an additional product that they may not want or need, which may not be advantageous to them. For example, if a store stipulates that to buy a popular DVD, a customer must also purchase a specific model of a portable TV, this creates a situation where the customer is restricted from choosing among the market's variety of portable TVs. This differs from product bundling, where multiple products or services are offered together at a more attractive price, such as cable companies providing cable, internet, and phone services as a package deal. Tied selling can reduce consumer choice and may come under scrutiny for potentially being anti-competitive.