The sellers.json framework is an initiative by the Interactive Advertising Bureau (IAB) aimed at increasing transparency in the programmatic advertising ecosystem to help prevent ad fraud. Here’s a detailed look into how sellers.json functions technically to achieve this:
1. Public Declaration of Seller Identities:
- Purpose: Sellers.json files are hosted publicly by ad exchanges, supply-side platforms (SSPs), and other intermediaries in the digital advertising supply chain. Each file contains a list of entities (publishers and intermediaries) that are authorized to sell digital advertising inventory on the platform.
- Content: The file includes key details about each seller, such as the seller’s
sellerId(a unique identifier for each seller within a platform), thename(legal entity name), thedomain(associated with the seller), and aseller_type(indicating whether the entity is a PUBLISHER, INTERMEDIARY, or BOTH). - Verification: This public disclosure allows buyers (through Demand-Side Platforms, DSPs) to verify the entities involved in selling an ad impression, ensuring that they are buying from legitimate sources.
2. Transparency in the Supply Chain:
- Sellers.json works in conjunction with another IAB initiative called SupplyChain Object (part of the ads.txt/OpenRTB specifications).
- SupplyChain Object: It provides a complete view of the intermediaries involved in the sale of a particular ad impression. Each link in the chain is represented by a node, and each node contains an identifier that matches an entry in a sellers.json file.
- Chain of Custody: By matching nodes in the SupplyChain Object with entries in various sellers.json files, buyers can trace the path of the ad impression from the original publisher to the final sale, ensuring no undisclosed parties are involved in the transaction.
3. Combatting Domain Spoofing:
- Domain Spoofing: One common form of ad fraud involves misrepresenting low-quality inventory as being from a high-quality, reputable domain (domain spoofing).
- Countermeasure: By verifying the sellers against their declared domains in sellers.json files, advertisers can ensure that they are buying inventory from the actual domain owners, reducing the risk of falling prey to spoofed domains.
4. Ensuring Authorized Reselling:
- Authorized Digital Sellers (ads.txt): Sellers.json complements the ads.txt standard, where publishers publicly list the entities authorized to sell their inventory. Buyers can cross-reference the seller information in sellers.json with the publisher’s ads.txt file to ensure that the intermediaries are authorized to sell the inventory.
- Direct and Reseller Relationships: Sellers.json can indicate whether a seller is direct (the owner of the inventory) or a reseller (an intermediary authorized to sell the inventory), providing further clarity and verification points for buyers.
5. Programmatic Accountability:
- By making the supply chain transparent, sellers.json forces entities within the ad ecosystem to operate with a higher degree of accountability. Illegitimate sellers and intermediaries find it harder to hide their tracks, reducing their ability to siphon off ad spend through fraudulent means.
Technical Implementation Considerations:
- Adoption and Accuracy: The effectiveness of sellers.json in preventing ad fraud depends on widespread adoption by all stakeholders in the digital advertising ecosystem and the accuracy and timeliness of the information provided.
- Integration with DSPs and Verification Tools: Demand-side platforms and third-party verification services use sellers.json in their algorithms and fraud detection mechanisms to evaluate the legitimacy of inventory before purchasing.
In summary, sellers.json increases transparency in the programmatic advertising supply chain by publicly disclosing seller identities, enabling buyers to verify the legitimacy of the sellers and trace the path of ad inventory through the supply chain, thereby helping to prevent common forms of ad fraud such as domain spoofing and unauthorized reselling.