What is ads.txt and why is it an OSINT goldmine?
ads.txt (Authorized Digital Sellers) is an IAB Tech Lab standard requiring publishers to declare every ad network, SSP, and reseller authorized to sell their ad inventory. The file lives at a fixed, predictable path — /ads.txt — on every monetized website. Each line contains an ad system domain, a publisher account ID, a relationship type (DIRECT or RESELLER), and optionally a certification authority ID.
The publisher account IDs are the real intelligence. A Google AdSense pub- ID or an AdX account number is shared across all domains owned by the same entity. If two seemingly unrelated websites share the same publisher ID, they almost certainly belong to the same operator. Archived ads.txt files extend this analysis back years, revealing past ownership, network migrations, and monetization strategies that current files no longer show.
What does sellers.json reveal?
sellers.json is the supply-side counterpart — hosted by ad networks at /sellers.json. It maps publisher account IDs to seller names, domains, and seller types (publisher, intermediary, or both). Cross-referencing an account ID found in ads.txt against the ad network's sellers.json can reveal the legal entity name behind anonymous publisher IDs.
OSINT applications of ad revenue archaeology
Combine the ads.txt Tracker with other Max Intel tools for deeper investigations: use Domain Recon to identify target infrastructure, WHOIS History to correlate ownership changes with ad network migrations, or Wayback Recon to see how a site's monetization evolved alongside its content. Cross-referencing publisher IDs across domains is one of the most reliable techniques for de-anonymizing website ownership networks.