One of the keys to breaking into a new market is to establish a strong word-of-mouth reputation among buyers. Numerous studies have shown that in the high-tech buying process, word of mouth is the number-one source of information that buyers reference, both at the beginning of the sales cycle, to establish their “long lists,” and at the end, when they are paring down their short ones.
Now, for word of mouth to develop in any particular marketplace, there must be a critical mass of informed individuals who meet from time to time and, in exchanging views, reinforce the product’s or the company’s positioning. That’s how word of mouth spreads. Seeding this communications process is expensive, particularly once you leave the early market, which in general can be reached through the technical press and related media.
— Crossing the Chasm, 3rd Edition: Marketing and Selling Disruptive Products to Mainstream Customers by Geoffrey A. Moore