Tom Murphy, responding to my post about a company paying bloggers to mention their service, doesn’t think it’s much to worry about. “I think it should be easy enough to spot if any marketing bloggers are in this program.  I think it would be quite hard to subtly post an entry on “hosted communications management services.”

Tom also agrees that the trend could lead to bloggers pitching less obvious products and services without identifying the pitch as advertising. I think it’s a real possibility. One reason blogs have grown in popularity is their appeal as alternatives to journalists who have lost the public’s trust. They have violated the code of ethics by which journalists are supposed to abide.

But at least journalists have a code of ethics to breech. No such code exists among bloggers, nor could one ever take root since blogging is not, for the vast majority of bloggers, a profession. If this approach to covert advertising becomes more commonplace—and it probably will—the credibility of every blog will be called into question. For example, I posted an item today about a product called Blog Torrent. How does anybody reading my blog know I wasn’t paid to place that item? (I wasn’t, but you don’t know that.)

If every blogger flags a paid placement as such, then there’s no problem. But with no incentive for every one of the millions of bloggers out there to do so, and a profit motive for some to keep it quiet, hoping every blogger takes the high road is just plain foolish.