One of the most frequently asserted defenses to an action under either the Sherman Act or the Clayton Act against a tying arrangement-a contractual limitation imposed by a manufacturer whereby the purchaser of the "tying product" agrees to purchase a related "tied product" only from the manufacturer of the tying product-has been that the tying was necessary to protect the good will or the integrity of the tying product. Whether the tied product is service for the tying product, another component in a system in which the tying product is used, repair parts for the tying product, or any other product related in some way to the functioning of the tying product, the basic defense is the same. It is that the tying product operates properly only when used in conjunction with the tied product, and that if the user of the tying product is not compelled to use the tied product it is possible that he will use an inferior substitute which will cause malfunctioning of the tying instrumentality and thus impugn the integrity of the product. It has generally been possible to reinforce this argument by showing that the malfunctioning of the tying product or the system in which it is used would not be readily traceable to the inferior quality of the substitute for the tied product, and therefore the user would be likely to blame the tying product for the failure to perform properly.
F. B. Kulp Jr.,
Tying Arrangements Under the Antitrust Laws: The "Integrity of the Product" Defense,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol62/iss8/7