Tying (commerce)

Tying (informally, product tying) is the practice of selling one product or service as a mandatory addition to the purchase of a different product or service. In legal terms, a tying sale makes the sale of one good (the tying good) to the de facto customer (or de jure customer) conditional on the purchase of a second distinctive good (the tied good). Tying is often illegal when the products are not naturally related. It is related to but distinct from freebie marketing, a common (and legal) method of giving away (or selling at a substantial discount) one item to ensure a continual flow of sales of another related item.