Coke, Sprint think word of mouth is good

From the ad:tech conference in Chicago:

Sprint/Nextel and Coca-Cola Co. are putting their money into word-of-mouth advertising, and they shared strategic details in a panel yesterday at the ad:tech conference in Chicago. One of the greatest challenges in this emerging tactic is tracking exact return on investment. "I don't track ROI," said Mel Clements, a brand manager of Coca-Cola. "We track the old-fashioned way and look at how many people have seen something and passed it to their friends."