Guardian US test underlines need for advertisers to enforce ads.txt

When Guardian US enforced ads.txt for both types of ads, the money was only spent on the publisher’s own inventory, as intended. Without ads.txt enforced, only 28 percent of Guardian US’s video ad dollars were actually spent on its inventory, with 72 percent going to unauthorized exchanges and supply-side platforms and never making it into the publisher’s coffers.

“We did see some alarming stats come against pre-roll,” said Brendan Cleary, vp of programmatic sales and ad operations at Guardian US. He declined to say how much money Guardian US spent in the study but said that it spanned enough inventory for the publisher to be confident in the study’s results.

There was less discrepancy when it came to the display ad buys. Despite not enforcing ads.txt, 99 percent of the revenue that was bought against display came back to the publisher, said Cleary. He wasn’t sure why, but the reason may have to do with ad fraudsters seeing a bigger potential score in video than display, in the same way that a thief is more likely to loot a Tiffany & Co. than a Claire’s.

“Video has been subject to more fraud than display because video is a more supply-constrained market. If you surface some video inventory, it’s going to get a pretty high fill and higher CPMs,” said Curt Larson, chief product officer at Sharethrough, an ad tech firm that specializes in native advertising.

Through its study, Guardian US hoped to demonstrate the importance of advertisers’ enforcing ads.txt to ensure that their ad dollars go to the publishers they are intended for. Advertisers are increasingly adopting and enforcing ads.txt, but the extent of that enforcement has been limited by issues, such as errors in publishers’ ads.txt files and current lack of support for mobile in-app inventory. Because of these issues, major ad buyers such as Publicis Groupe’s programmatic hub, Publicis Media Precision, have not yet been able to wholly limit clients’ programmatic dollars to ads.txt-compliant paths, though it has required publishers in its private marketplaces to have ads.txt files.

“We always understand that the open market will be valuable for both buyer and seller. We felt that, especially based on the findings from this study, without directly working with a publisher in regards to pre-roll, budgets can and will be lost,” Cleary said.