‘We’ve reached critical mass’: Advertisers see more options to buy ads only from publishers that have adopted ads.txt

Advertisers’ enforcement of ads.txt is still most prominent in private programmatic marketplaces, where issues like domain spoofing are considered less of an issue because the participating publishers have been vetted by the advertiser, its agency or the ad tech firm operating the private marketplace. For example, Publicis Groupe’s programmatic hub requires publishers in its private programmatic marketplaces to have ads.txt files. So does demand-side platform MediaMath for its “curated market.” And Digital Content Next’s TrustX also requires publishers to have uploaded ads.txt files to sell inventory through its nonprofit ad exchange.

However, ads.txt’s real value for advertisers lies in making sure the money they spend and the ads they run through open programmatic marketplaces make it to the intended publisher. As The Guardian US recently showed, without ads.txt being enforced, more than 70 percent of an advertiser’s programmatic pre-roll video dollars can be siphoned by sites posing as the intended publisher.

Advertisers’ enforcement of ads.txt in the open marketplace had been hampered by the question of whether enough publishers have uploaded ads.txt files. But that question has been answered. “We’ve reached critical mass,” said Kerwin.

In April, ad tech firm OpenX said that roughly 60 percent of comScore’s top 1,000 publishers in the U.S. have uploaded ads.txt files to their sites. Google, which in November 2017 began using ads.txt files to filter out unauthorized inventory, has seen publisher adoption increase as well through its crawler that checks more than 30 million domains each day for ads.txt files. In January, roughly 164,000 sites had uploaded ads.txt files; now, the figure has surpassed 600,000 domains, according to Google’s head of GDPR and data trust, Pooja Kapoor.

“Adoption is currently at roughly 80 percent on the exchanges that [Google’s DSP] accesses and over 90 percent of the publisher inventory on the Google Ad Manager side,” she said.

No longer limited by adoption, now the enforcement can begin.

“Up until recently, our DSP partners have been hesitant to commit to rolling out any product/bidding enhancements until ads.txt adoption rates increased. We are now hearing from some of our partners that we now have the ability to only target our programmatic dollars on ads.txt inventory,” said Nichola Perrigo, vp and director of digital media at RPA.

Among the DSPs that have enabled advertisers to only buy ads.txt-authorized inventory is MediaMath, which added the option in late April, according to Lewis Rothkopf, gm of media and growth channels at MediaMath. More recently Google’s Display & Video 360 (née DoubleClick Bid Manager) has followed suit. On June 27 Google’s DSP added an ads.txt-only option for buyers to block any sites that hadn’t adopted ads.txt from carrying their ads. More than 15 percent of the new line items that ad buyers have created for their campaigns have enabled the ads.txt-only option since it became available, said Kapoor. She said that she did not have any data to share regarding how ads.txt-only enforcement has impacted ads’ reach, performance and pricing.

The ads.txt-only option is turned off by default, but Google aims to make it enabled by default by the end of 2018, said Kapoor. The ads.txt-only option “is a step towards our end goal, which is to move to a default authorized-only state,” she said.

However, for advertisers to move to ads.txt-only buys in the open marketplace, first they will need to see how going ads.txt-only affects their open-marketplace buys. RPA is currently running tests with the DSPs it uses “to determine how large of a performance impact this has on our media,” said Perrigo. Kerwin will also look to test the ads.txt-only options to see if there is any impact on the scale of clients’ campaigns. “As this rolls out as a lever in the DSP, we’ll be able to do some testing and make sure our advertisers and clients are still hitting the goals they need,” she said.