Word-of-mouth (WOM) marketing, also known as referral marketing, is a powerful tool that businesses can use to promote their products and services. It is a type of marketing in which satisfied customers share their positive experiences with their friends, family, and colleagues. WOM marketing is often considered to be the most effective form of marketing because it is based on trust, and people are more likely to believe and act upon recommendations from people they know and trust. In this essay, we will explore the effects of WOM marketing in detail, including its benefits, limitations, and best practices.