Ads.txt: learnings and what's on the horizon

Business man at his desk.

By Brian Sim, Sr. Product Marketing Manager, Verizon Media

Over the past year, we've taken significant steps across our supply and demand platforms to adopt and evangelize ads.txt and improve marketplace quality and transparency.

Our DSP began filtering out all unauthorized sellers based on ads.txt information early in 2018. Our publisher platforms released features to enable DSPs and advertisers to filter out unauthorized requests. And based on the insights we've gathered over the past several months, we're excited to announce that we'll be enabling platform-wide filtering of all unauthorized supply on the Video SSP starting in March.

So what have we learned?

Advertisers have shown overwhelming interest in only buying authorized supply.

Ads.txt has spurred a dramatic shift in buying patterns, with advertisers increasingly moving ad dollars to authorized supply. In fact, on the Video SSP, advertiser spend on authorized sellers grew from 32% to 91% in less than a year. And while there's some tolerance for uncategorized supply (7% of spend), there's nearly none for unauthorized supply. In order to maximize ad revenue, publishers need to support ads.txt, and ensure their authorized seller relationships are characterized accurately.

ads.txt Advertiser Spend Final v2

Publisher adoption has been dramatic, but there's still work to be done.

Publisher adoption of ads.txt dramatically increased mid-year, spurred by bidders moving to filter out unauthorized supply. Our account teams also worked closely with publishers to ensure Oath's ad platforms were listed as authorized sellers. In addition to decreasing unauthorized supply, we've also seen a significant drop in the number of uncategorized opportunities - these are impressions from publishers that don't have an ads.txt file yet.

Today, over 65% of market opportunities available on the Video SSP are from authorized sellers, which falls in line with the latest data on publisher adoption from Pixalate¹ (37% of Alexa Top 5,000 sites with ads.txt, 77% of Pixalate Top 5,000 sites with ads.txt). These adoption trends are a good sign, but there's still a good number of publishers that need to adopt ads.txt.

ads.txt VIdeo SSP Supply Final

There's no magic bullet for OTT apps yet.

While spoofing - the act of misrepresenting domains - on mobile and CTV apps is less common than on desktop supply, it still exists. To protect against unauthorized app supply, we revamped our process for reviewing and onboarding mobile apps. By removing most ad network supply, and passing ad opportunities from app developers and trusted ad networks, we've been able to better position ourselves to avoid sending mobile app supply that is more susceptible to unauthorized selling and spoofing.

Now what are we looking forward to in 2019?

SSP platform-wide pre-filtering of all unauthorized supply.

To date, we've allowed buyers to decide whether or not they want to receive unauthorized supply. As the data above showed, their actions have been loud and clear: they don't want unauthorized supply.

And we've been listening. We've made the decision to stop sending all unauthorized opportunities to DSPs (previously, we allowed DSPs to make the decision). This platform-wide filtering will start being enforced on the Video SSP in early March, and will prepare us to be certified against TAG's Anti-Fraud Guidelines. We'll enable this policy on the Oath SSP, as well, once our consolidation work is complete. Our ads.txt policies are continually evolving. We're also exploring segmenting authorized direct and indirect supply, and whether to also block uncategorized supply. We're confident these steps will further improve buyer efficiency and transparency in our marketplaces.

Developing a better solution for mobile apps and CTV.

Ads.txt hasn't been as relevant in the app sphere, but this is changing. The IAB released a proposed spec for expanding ads.txt to cover mobile and CTV apps (app-ads.txt). App-ads.txt would work in conjunction with app stores to link back to the ads.txt file on an app developer's website. We're closely following the IAB spec, and will actively work to push adoption of app-ads.txt once it has been finalized.

Planning for the future with ads.cert.

Our inventory quality and safety product teams have been closely following the development of ads.cert (PDF). Whereas ads.txt verifies supply on a publisher level, ads.cert allows advertisers to verify supply at the bid request level. This means advertisers can ensure that the video ad request they receive is exactly as represented, and isn't actually a repackaged display ad request, for example. Ads.cert requires sellers and buyers to upgrade to the OpenRTB 3.0 spec, so widespread adoption is still a ways away. However, it's a development we're excited about, and we look forward to adopting.

¹Source: Pixalate Q3 2018 Ads.txt report