• by Joe Mandese  @mp_joemandese, October 1, 2012

At a time when the ad industry is lobbying publishers to disclose the “viewability” of their ads, publishers seem to be going in the opposite direction and making the process more opaque and less transparent, according to the findings of a comprehensive report tracking the supply and demand of ads bought through exchanges in the real-time bidding (RTB) marketplace. The report, independent agency trading desk Accordant’s “Q3 Market Pulse,” found that only 29% of the biddable inventory made available during the third quarter disclosed whether the ads were viewable, down from 32% in the second quarter, and down from about 40% in prior quarters.

The finding, which comes as major ad agencies, advertisers and trade groups are pushing to make “viewability” – meaning advertisers would only pay for ads that users can actually see -- the industry standard for online advertising, indicates that at least for the short run, some publishers are actually making that harder to discern by not making data about the viewability of their ads available when they are bought.

“Publishers can opt to set that setting and disclose that position, but some publishers have actually tightened back the reins,” explains says Craig Schinn, vice president-analytics at Accordant. Schinn said while it’s not entirely clear why publishers are making their viewability data more opaque, he speculated that at least some of them see it as a short-term means of “protecting their CPMs,” or the cost-per-thousand advertisers pay for their ads, by “hiding the junk and not telling you it’s below-the-fold” and therefore not viewable.

Schinn estimated that historically only about 60% of that data was “hidden” in the past, and now it’s risen to 71.”

Schinn noted that the data isn’t 100% apples-to-apples, because different mixes of publishers’ inventory are available in the exchange marketplace that trading desks like Accordant buy inventory on, but Accordant’s report is pretty representative of the current marketplace. The report analyzes actual buys made across 425,000 sites covering display, video, mobile and social network ads.

The findings also suggest that publishers who do not disclose the viewability of their ads may actually be hurting themselves, because the ones that are making their data more opaque, including “a big portal,” actually perform better in terms of how well their ads perform. Accordant learned this, because while overall “click-through” rates improved during the third quarter, the average “cost-per-action” actually got worse. Accordant’s Schinn surmised that occurred because sites like the big portal that were precluded from the buys because they did not disclose data about the viewability of their ads, actually perform better.

“We think they’re hurting themselves by blocking the data, because they’re blocking themselves from being on the plan,” explained Accordant CEO Art Muldoon, adding, “We have clients who only want viewable ads, and if we don’t have that data, we can’t put them on the plan for those clients.”

Muldoon said the findings have big implications for the so-called RTB marketplace, especially as the industry heads into Advertising Week this week, where a number of events and panel discussions will be trying to shed light on the subject of viewability. Among other things, he noted that the trend data shows that publishers are actually moving in the opposite direction. Another big issue, he said, was the implications of so-called “attribution models” that advertisers and agencies use to determine what parts of their online campaigns actually generated results from users.

If trading desks stop buying inventory from publishers who fail to disclose the viewability of their ads, and the average performance of the ads they do buy declines, he said those attribution models will need to be adjusted.

As part of its third-quarter analysis, Accordant also tested three major third-party research suppliers who claim they have developed methods for independently measuring the viewability of publishers’ ad inventory, but he said that part of the test yielded mixed results, and that only one of the suppliers appeared to be generating relatively accurate data.

Despite these shifts, Accordant found that overall demand for the RTB marketplace continues to grow, and that the amount of inventory purchased through the marketplace nearly doubled during the third quarter, rising 88% over the third quarter of 2011. While that’s a slightly slower pace than the rate of expansion during previous quarters, Accordant executives said it is still extremely healthy growth as the marketplace “matures.”

Interestingly, the average price paid by advertisers grew only a modest amount, with CPMs rising about 2% during the quarter. Accordant’s Muldoon said that indicated that while the volume of RTB inventory is expanding rapidly, it is being driven by “balanced” demand and that the marketplace appears to be in equilibrium.