Industry Perspectives

Why We’re Supporting Ads.txt

Blog Post
The AppNexus Team

Quality content is hard to make. It takes great creators – journalists, artists, filmmakers, game designers, and the like – who can make a story come to life. It also takes skilled developers who can keep a web site running smoothly and ad ops professionals to monetize the site’s content. So, when a publisher has advertisers willing to pay for their inventory, that publisher can’t afford imitators siphoning off those ad dollars. And the advertiser certainly doesn’t want to waste their money on such an imitator; they want to reach an audience that actually exists and reward the publisher for their great work.

But despite the success of recent measures to address these issues, the IAB says that bad actors are still able to trick buyers into purchasing fake impressions.

At AppNexus, we want to make sure that publishers and their authorized partners are fairly compensated for their inventory, and that advertisers get what they pay for. That’s why we’re supporting the IAB’s new ads.txt project, which promises to add more trust and transparency to the online advertising ecosystem.

Below, we lay out how ads.txt works, explain why we’re supporting it, and tell publishers how to use it.


What is ads.txt?

Ads.txt lets publishers tell all buyers exactly which platforms and sellers are authorized to sell their inventory.

The way it works is simple.

Publishers place a public-facing text file on their web server that lists all of the SSPs, networks, and exchanges they’ve agreed can sell their impressions, along with those sellers’ exchange member IDs and designations of whether they’re a direct seller or a reseller. Publishers can easily update their ads.txt file any time they add or subtract a partner. You can check out Business Insider’s ads.txt file here for an example.

From there, DSPs and SSPs will regularly crawl these files to confirm for buyers which platforms they can use to buy legitimate inventory from any publishers they want to work with.


Why is AppNexus supporting ads.txt?

The intent behind ads.txt is consistent with our longstanding goals around inventory quality. Right now, we proactively work with many publishers to manually identify authorized inventory sources across the SSP landscape. We also created AppNexus Direct, a collection of publisher-owned and operated sellers that buyers can target on AppNexus to find a direct path to supply.

We like ads.txt because it puts publishers in the driver’s seat and lets them tell all buyers where they can safely find their inventory without the aid of a third party. While most transactions are safe, having a single, industry-wide source of truth makes it a lot harder for bad actors to fool advertisers with fake impressions and cheat publishers out of money that should be theirs.


How can publishers get started with ads.txt?

We’ve posted a guide for publishers to stand up their own ads.txt file on our public wiki. The wiki also provides guidance to intermediaries on how they can advise their publisher partners on curating their ads.txt files. It’s a quick and easy process, so we encourage you to get started right away.

It’s only been a few weeks since ads.txt was released, but so far we’ve tracked nearly 50 sites that have adopted it, including industry leaders like Business InsiderThe Economist, and The Washington Post. We’re ready to help our publisher customers join them when they’re ready, and look forward to remaining a part of the conversation as ads.txt evolves and scales.