There’s more to ads.txt than slapping together a list of partners who are authorized to sell your inventory. Before you put that list together, it’s important to do some testing and spot-checking.
A publisher is at risk regardless of whether or not they run programmatic – regardless of whether or not you sell ads on your site, even. Counterfeiters are taking advantage of publishers’ good names –misrepresenting their inventory as yours, while theirs is on fake websites, on spoofed domains, and/or surrounded by garbage content. And whitelisting by site name or URL is not enough to stop these tricks.
So, here’s what publishers should do: Partner with a DSP. Look for inventory that’s marked as “yours.” Check to see whether the type of ad units available matches what you know you have on your sites, and that the number of available impressions also matches. Search your URLs and site names, and see if what you find matches what you know to be your URLs and publisher IDs. Then… buy your inventory!