This is what happens when you let advertising people stray into what ought to be PR territory.There were reports last week that employees at radio stations around the US are angry about a new deal between America Online and Viacom's Infinity Broadcasting. The deal includes a $15 million ad buy and a controversial arrangement whereby stations receive the AOL for Broadband service in exchange for DJs promoting those broadband offerings on air. An Advertising Age article quotes a Viacom staffer who feels editorial integrity is being compromised: "It is somewhat a blurring of the line, most definitely...The biggest difference between this and almost anything else is that [in other cases] you'd say 'sponsored by' or 'brought to you by.' That's not showing up in this at all." On one hand, I suppose PR people should find deals such as this flattering, because implicit in the arrangement is the acknowledgement that editorial mentions have a value and a power beyond that of a paid commercial. But there's a troubling side to this that outweighs any satisfaction we might draw. The very thing that makes PR valuable and powerful - its credibility - is compromised each time a deal like this one is reached. The Infinity folks don't seem to grasp that. A spokesman says he doesn't see a problem: "It's advertising. They're paying us for it, and that's that. I'm not aware of any controversy." (The fact that listeners are being misled, through a lie of omission, is of no concern, apparently.) There is a communications continuum with control at one end (paid ads) and credibility at the other (earned media). You can never increase your control over the message without weakening its credibility. And anything that blurs the line between paid and earned media undermines the credibility of journalistic messages. The trend of the past decade is for controlled messaging to become less effective, as consumers become more sophisticated, while credible messaging is at a premium. It's a trend detailed in the Al and Laura Ries book The Fall of Advertising and the Rise of PR, and one of which most ad agencies and brand marketers are quite conscious, which explains their interest in trying to extract "public relations" value from their commercial buys. The Public Relations Society of America, which has been taking a stand on controversial issues recently (its comments on the FCC hearings last month are a case in point) should address this issue because it has the potential to undermine the already fragile integrity of a key third-party endorser, and ultimately to blur the line between advertising and PR in a way that robs us of our most important asset: credibility.