The phrase “Word of mouth is the best medium of all” means that personal recommendations and referrals from satisfied customers are the most effective way to spread the word about a product or service. In other words, people are more likely to trust the opinions and experiences of their friends, family or colleagues than they are to trust advertising or other promotional efforts. This saying highlights the importance of positive customer experiences and the power of social influence in driving business success. It suggests that companies should focus on creating high-quality products and services that people will want to talk about and share with others, rather than relying solely on traditional marketing channels. By generating positive word of mouth, companies can build a strong reputation, attract new customers and ultimately grow their business.