Best Buy, Gap, Gallery Furniture, and Old Navy, four of Houston''s top retailers, have agreed to participate in Arbitron’s upcoming trial of the portable people meter ratings service in the market, Arbitron announced Tuesday.

The four retailers, which operate more than 50 store locations in Houston. They will encode the audio that plays in their stores using the unique PPM identification codes supplied by Arbitron. According to Scarborough Research, these outlets in aggregate are visited by at least 63 percent of the adult population over the course of the past year. Arbitron is working to bring additional retailers on line for the Houston PPM demonstration.

These are developments that savvy public relations pros are paying close attention to as they are likely to have sweeping implications on the public relations field. As KDPaine & Partners pointed out in their recent newsletter, KDPaine''s Measurement Standard:

The interesting news is the huge social implications that this technology has. Nielsen ratings have for years determined what we get to watch on television. The problem is that fewer and fewer people are watching television. More and more are getting their news via the Internet, and their entertainment via their computer and/or their iPod. So as the numbers from the PPM roll in, chances are that advertisers will reallocate their dollars away from television and focus them on other forms of media.

This could be great for word-of-mouth marketing, PR and the Web, if, as we assume, the PPM data shows just how much more influential they are than they now get credit for. However, any major shift in audience will also mean that advertisers will begin shoving products at us via whatever new medium ends up on top.

The retailers join National CineMedia, a venture of AMC Entertainment and Regal Entertainment Group, which will also be participating in the trial by encoding The 2wenty, a short-form pre-fature program that airs on 46 movie screens in two theaters in Houston. Among the media, 94 percent of all outlets have agreed to encode including 44 out of 51 radio stations, all 16 TV stations, and all 46 cable networks. In radio, the two holdouts remain Cox Radio and Radio One.

“By encoding in-store audio as part of the PPM market trial in Houston, we’ll be able to demonstrate how the PPM can measure the store traffic that advertising generates,” said Pierre Bouvard, president of PPM for Arbitron. “Without adding any additional burden on a PPM survey participant, we would be able to measure the retail visits as easily as we measure the marketing effort. This will enable PPM to provide powerful measures of return on investment and accountability.”

Arbitron hopes to bring additional retailers online for the Houston PPM trial, which is on track to reach its full panel size of 2,100 consumers in time for the July TV survey.

Arbitron has been testing the PPM, which tracks consumer exposure to media and entertainment by monitoring audio encodes embedded in the content, since 2000. Although Nielsen Media Research has been cooperating with Arbitron to develop the PPM and has an option to form a joint venture, Arbitron is managing the Houston trial on its own. Nielsen is owned by Mediaweek parent VNU.

Next month, the radio ratings firm plans to present a proposal to commercialize the PPM as soon as April 2006. The decision to announce a “fast-track plan” followed Clear Channel’s request for a proposal for an alternative ratings service to Arbitron’s current diary methodology.