What is apparently a Google experiment in a new way to determine search relevancy, seemingly commercial listings are appearing among organic search results, but demarcated by horizontal lines, reports ClickZ. A Google spokesperson assured ClickZ that the results are not paid listings. The listings are "very commercial-looking results," according to Mike Levin, VP of Connors Communications Interactive Group, which claims it has examined 50 keywords and phrases that delivered such demarcated, but unlabeled, results.

Observers point out that the new listings approach could have significant impact on search optimization.

Levin says the link redirects indicate that the results are being tracked, but not with all the code that's used to track AdWords placements. "So it is an experiment in AdWords relevancy that changes the current page rank approach," he surmises.

"So they are taking positions 6,7 and 8, they're drawing horizontal lines and they are doing something else in that spot. Which on its own has tremendous implications for the organic search optimization field," Levin is quoted by ClickZ as saying.