Final answer:
Frank's recommendation and coupon sharing is an example of 'pass-along,' a form of word-of-mouth endorsement.
Step-by-step explanation:
Frank's recommendation of Mercury's unique lighting solutions to Osvaldo, including giving him a coupon for a discount, is an example of pass-along.
This term refers to the act of sharing information or benefits, such as a coupon or discount code, from one consumer to another, especially as a form of word-of-mouth endorsement. It is a way for satisfied customers to organically spread the word about a company's products or services, thereby potentially increasing the company's customer base without the direct involvement of traditional advertising channels by the company itself.