(Business 2.0) – Dollar for dollar, the best advertising is word of mouth--as long as the word is good, that is. Handspring's new Treo 600 cell phone/PDA combo, which went on sale in mid-October, is one product that seemed destined to live or die by the buzz. Earlier Treo models were considered clumsy, and Jeff Hawkins, Handspring's iconoclastic product designer and chairman, had promised that the 600 would be more phonelike and come with extras like a camera and an MP3 player. As the product readied for launch last summer, there was no question that it would be talked about. The only question was what people would say.

To measure the extent of the noise that the Treo generated, we asked Biz360, a San Mateo, Calif., media analysis software company, to track mentions of the phone in all print and electronic media, including weblogs, from the phone's European launch in early September to the present.

The results, charted below, show that the hype machine worked very much in the Treo's favor. Handspring got the gears turning when Hawkins nonchalantly carried a 600 into a corporate publicity shot in June. As Handspring PR chief Brian Jaquet anticipated, gadget websites like TreoCentral.com glommed on to this tantalizing glimpse like the CIA to spy photos of North Korean nuclear bomb factories. "It really fanned the flames," Jaquet says.

The crucial next phase was the reviews. Although Handspring obviously can't control what's written, Jaquet and his team did their best to tilt the odds in the Treo's favor. Just two dozen handsets were made available, largely to reviewers who had previously been kind to Handspring. Before handing over the sets, Handspring provided each reviewer a personal liaison from the local wireless carrier to make sure the writer would have a smooth experience. Reviews were embargoed until Sept. 18 for maximum impact, and as it turned out, all early notices were favorable.

Phones were also sent to celebrities. As of late October, publicity had exposed as many people to the Treo as would $265,000 worth of advertising. The figure is understated, though, since no ad can match the persuasive power of praise from a high-profile reviewer or of a plug from a starlet. That truly is priceless. --DAMON DARLIN