Final answer:
A price reduction offered by the seller to dissatisfied buyers who agree to keep the goods is known as a concession or price adjustment.
Step-by-step explanation:
When dissatisfied buyers agree to keep goods instead of returning them because the seller offers a price reduction, this is known as granting a concession or a price adjustment. This is a common practice in the goods market, particularly when buyers cannot physically inspect the products before purchase, such as with online shopping or mail-order catalogs. Sellers may also offer warranties or service contracts as an additional promise of quality, and to provide assurance to the buyer that any future issues with the product will be resolved.