Word-of-mouth is one of the most powerful types of marketing, but also one of the toughest to execute and measure. But with eight years under its belt, word-of-mouth agency BzzAgent can now measure reach, return and change in sales to determine the value of a word-of-mouth for brands, the company’s CEO Dave Balter told Beet.TV at the Digitas New Front in New York in early June. The company relies on a network of nearly 600,000 agents and volunteers who try products and tell others about them for clients such as Hershey’s, Dunkin’ Donuts, TVGuide and even the “ManGroomer” product for shaving a man’s back, Balter said. “The goal of an agency is to stimulate places that aren’t as organic,” he said. Daisy Whitney, Senior Producer Less