Everyone talks about how word of mouth is the best form of marketing that there is.
It's about having a product or service so good that people talk about it (for free!) and bring their friends.
The thing about word of mouth marketing is that its an outdated term. People talk about it like its a medium in and of itself, when in actuality its a natural byproduct of successful marketing.
It would be like a business saying that their number "form of business" is profit; it may be true but its not really a helpful action item. No profit is actually derived from creating value. And just like profit, word of mouth is a byproduct of marketing.
So when people talking about word of mouth marketing, they are really talking about a product or service that is worth talking about, yet they never actually do anything about it. You make something worth talking about it by being something that people actually care about.