ads.txt and Authorized Sellers

Why ads.txt matters for your CPMs and fill rate, what the three types of entries in your Advlume ads.txt file mean, and how to keep it current as demand partners change.

ads.txt (Authorised Digital Sellers) is an IAB standard that lets you publicly declare which companies are authorised to sell your advertising inventory. DSPs check this file before bidding, and inventory from domains with missing or incorrect ads.txt entries typically receives lower bids or none at all.

Why ads.txt matters

Without ads.txt, a DSP has no way to verify that the inventory it is buying actually belongs to you — it could be a spoofed domain serving fraudulent impressions. ads.txt closes this gap by providing a cryptographically-verifiable (via sellers.json cross-reference) chain of authorised resellers.

In practical terms:

  • DSPs that require a valid ads.txt entry (most major ones) will not bid on your inventory if your file is missing or does not include Advlume's entry.
  • An incorrect file can suppress demand even if the issue is a small typo.
  • GAM will show a warning in your Ad Manager account if it detects a missing or incomplete ads.txt.

What goes in your ads.txt

Your Advlume ads.txt includes three types of entries:

  1. IAB directives:
    • ownerdomain=yourdomain.com — declares that you own this domain
    • managerdomain=advlume.com — declares Advlume as your ad network manager
  2. Advlume reseller entry: advlume.com, {your_seller_id}, RESELLER — authorises Advlume to resell your inventory. The seller_id matches your entry in advlume.com/sellers.json.
  3. Demand partner entries: One line per SSP/DSP connected to your inventory (Magnite, Index Exchange, OpenX, PubMatic, Xandr, Criteo, etc.), in the standard domain, publisher_id, DIRECT/RESELLER format.

How to set it up

See the step-by-step instructions in ads.txt Setup Guide. The short version:

  1. Go to Settings → ads.txt for your site in the Advlume dashboard.
  2. Copy or download your personalised ads.txt file.
  3. Upload it to your domain root so it is accessible at https://yourdomain.com/ads.txt.
  4. Click Verify in the dashboard to confirm the file is reachable.

Keeping it up to date

Advlume's demand partner list evolves as new bidders are onboarded. When Advlume adds a new demand partner, new ads.txt entries are required. The dashboard will notify you when your file is out of date. Check Settings → ads.txt periodically and re-upload when prompted.

Further reading

Previous What Happens When IVT is Detected

Last updated 2 months ago