• by Wendy Davis  @wendyndavis, June 12, 2006

Marketers who buy ad inventory from networks on a cost-per-performance basis might end up paying more than once for the same customer, according to a study by aQuantive's Atlas.

The Atlas report concluded that marketers should use third-party networks--such as itself--to serve ads when the buy is on a cost-per-performance basis.

The study, "The Hidden Cost of Pay-for-Performance Media" by Young-Bean Song and Jed Fowler, found that different ad networks frequently take the credit for the same customer who converts, for example, purchasing a product online. For instance, if a customer sees two different ads, served by different ad networks, and then purchases the product advertised within a set period of time--within, say, 24 hours of viewing the ads--each network claims it's responsible for that conversion.

For the study, Song and Fowler conducted an analysis of 10 campaigns, involving 49.4 million impressions, that ran last October and November. The study found an average duplication rate of 170 percent, with rates per campaign ranging from 26 percent to 379 percent. Atlas calculated the potential overpayment per campaign as $255,000, with a range from $15,000 to almost $1 million dollars; that calculation assumed that marketers paid the same conversion fee for those who clicked-through to convert as for those who viewed an ad and converted later.

Atlas actually served all of the ads in the study, so it caught the duplications and the marketers didn't overpay, Song said. He added that most marketers that use Atlas for ad-serving don't currently do so when they're dealing with remnant inventory purchased by networks.