Everything You Need to Know About Ads.txt Files

Ads.txt may not be a new concept, but it’s something that we need to remember to review. As a refresher, ads.txt is a text file that publicly declares the ad partners that can sell your inventory and it ensures that your digital ad inventory is only sold through sellers who have been authorized. 

There are some important steps to take to ensure that you’re optimizing your ads.txt file capabilities. 

Below, we share the top 3 reasons why you should keep your ads.txt file up to date, as well as the steps you should take to get the most out of your ads.txt file.


3 Reasons Why You Need to Keep Your Ads.txt File Up to Date:

1. You receive more advertiser spend

Platforms update default buyer settings regularly, so updating your ads.txt files ensures that you are eligible for all platform ad campaigns. If more advertisers have the capability to bid for ad space, this results in more revenue for you. 

A regular cadence of updating your ads.txt will ensure you know who is authorized to sell your inventory and guarantee you are not leaving ad dollars on the table. On occasion, DSP/SSP partners sunset or update their ads.txt lines. You always want to have the most up to date lines to prevent any loss in revenue.

2. Buyer verification

When you keep your ads.txt files updated, buyers can then confirm that they are buying from a verified source.  If you are no longer working with a particular seller/reseller or have placed them on your “naughty list”, it is a best practice to update your ads.txt and remove that seller from your file. It’s a good way to make sure they can no longer represent your inventory to buyers. 

3. You earn more cookieless revenue

Unlike highly competitive cookied reseller lines, cookieless reseller lines drive competition to your under-monetized inventory. Don’t miss out on demand from over 10 DSPs that target  your unaddressable inventory.


3 Steps You Should Take to Keep Your Ads.txt File in Check: 

1. Conduct regular monitoring

Checking if any partners are missing or if there are mistyped numbers, symbols, etc. These seemingly small issues could, quite literally, cost you. Errors or missing ads.txt lines could lead to consistently low buyer bid rates. Low bid rates lead to fewer ad impressions or low fill rates which then leads to lower revenue.   

2. Maintain ongoing vendor communication

Schedule bi-weekly/monthly check-ins and QBRs with your most valued SSP partners to see what’s new, bringing value or potentially not working. 

3. Cookieless reseller lines

Unlike resellers for cookies, cookieless reseller lines increase competition for your undervalued supply.


If you are a 33Across partner, you can update your ads.txt file here.


Who is 33Across?

    33Across makes the programmatic advertising ecosystem work without cookies, across supply-side platforms, demand-side platforms, publishers, data companies, agencies, and everything in between. Leading global advertisers, platforms, and publishers rely on 33Across to move past cookies and reach consumers in a simple, fair, and transparent manner.