• by Joe Mandese  @mp_joemandese, July 25, 2012

In a potentially troubling indicator for the world of marketing at large, Nielsen this morning reported a revenue decline of 1% for the second quarter of 2012, attributing it primarily to a 3% decline in its so-called “Buy” operations, which supply data to marketers on consumer purchasing patterns.

Nielsen executives said the declines were impacted by international currency conversions and said total revenues actually grew 4% on a “constant currency” basis, but even so, the quarter doesn’t exactly bode increasing demand for the kind of marketing research data that Nielsen supplies.

On the plus side, Nielsen said revenues for its “Watch” operations -- the ones that report data on consumer media usage -- increased 2% during the quarter, and 3% on a constant currency basis.

One thing that is not contributing much, if any, significant revenues to Nielsen is the Online Campaign Ratings it has been aggressively pushing marketers and agencies to embrace as the official trading currency of online media buys.

Nielsen CEO David Calhoun conceded that he personally “underestimated the agency role” in the adoption of the new online ratings data, and especially their ability to integrate the data into the way they buy media.

“It’s taken longer than I’d like,” Calhoun said about the adoption of the online ratings data, but I really do like the penetration and the confidence we are seeing in each of the necessary constituents.”

Calhoun no doubt was alluding to the program Nielsen undertook to provide the online ratings data to big clients for free for a trial period in the hope that they would eventually become paying customers. But he told analysts that he doesn’t expect the online ratings to become a significant contributor to Nielsen’s revenues until 2013.

Calhoun said the initial impact would likely be in the online video advertising marketplace, because it is the “higher value component.” He implied that advertisers and agencies already began integrating those ratings in their audience delivery guarantees for upfront advertising deals involving online video buys.

Calhoun also implied there was some reluctance on the part of some publishers to embrace the online ratings, because they differ from the previous metrics they used to sell advertisers and agencies with, and that in some cases they are reporting lower numbers.

On the other hand, Calhoun said other publishers for whom the online ratings represent “very, very well, it’s a very good thing.” He singled out Facebook, which ironically is also the primary source for the panel that Nielsen uses as the basis of its online ratings.

But the big hiccup in adoption of the online ratings, Calhoun reiterated, was ad agencies, which he described as “the crowd that stands between everybody.”

“They have to learn how to vet it into their systems, how they buy differently -- do they want to guarantee both mediums,” he said, adding that a few shops, most notably GroupM, have “jumped out of the gates.”

“They’re all beginning to understand the accountability metric,” Calhoun said. “They tell me every day to be patient, just be patient. This is the right way to build a currency.”