A. Anyone marketing goods, services or ideas. I know of no business or industry where word of mouth is not the dominant marketing force. Any business or service ultimately lives or dies on its reputation. To understand why it is so effective, you must see beyond the illusion that advertising and salespeople directly cause sales. The reality is that these conventional marketing methods usually create interest at most.
People then talk with friends, colleagues and trusted advisors.
They want to check out whether what is being claimed by the company is actually true. This is the process of word of mouth that intervenes between communication from the company and actual adoption of the product, service or idea. While there are occasional instances of direct influence from company to customer, usually word of mouth is the actual trigger to purchase, unobserved by the company. The most important reason why word of mouth is so effective is the least understood. Word of mouth is a substitute for experience.