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What is Sellers.json

Sellers.json is a file used by a supply-side platform's (SSP) website that provides information about all the authorized sellers. Sellers.json was created by IAB to increase transparency in the programmatic advertising landscape, to help identify unauthorized sellers, and to prevent fraudulent activities.

In the past, there were cases of invalid sellers claiming to represent legitimate publishers resulting in ad fraud and loss of ad revenue for both publishers and advertisers. This file was introduced to combat these issues.

How does it work

SSPs and ad exchanges can host the Sellers.json file on their servers and enable the demand sources to view the list whenever they need to. Demand sources can gain visibility into each step from when they send a bid response to when they serve ads to the publisher. This will also help demand-side platforms (DSPs) to make better buying decisions.

Sellers.json and OpenRTB Supply Chain Object work together to provide a transparent and easy way for advertisers to operate in the programmatic space.

OpenRTB Supply Chain Object

The OpenRTB Supply Chain complements Sellers.json in ensuring transparency and preventing ad fraud. The supply chain helps buyers gain visibility into all the parties involved in selling an ad space or making a bid request. It comprises a set of nodes that represent an entity in a supply chain.

For instance, let's say that the publisher and advertiser are on opposite ends of the supply chain. The ad network, DSPs, SSPs, or ad exchanges involved each represent a 'node' between the advertiser and the publisher. The advertiser is not in direct contact with the publisher and instead relies on the information provided by the intermediaries or ad networks.

Since there are many third parties involved, there is a risk of ad fraud that can occur. Here is where Sellers.json steps in, and helps advertisers identify their supply sources with unique seller IDs and other information.

What does Sellers.json include

  1. Parent: The parent object contains all the properties of a Sellers.json file. They are as follows.
  2. Identifier: An optional field that allows sellers to communicate values like business or certification identifiers that a demand source requires to operate better.
  3. Seller: A list of publishers and sellers that the host has partnered with.

Importance of Sellers.json

  1. Transparency: Sellers.json allows the demand sources to view the entire list of legitimate suppliers. This will help them make a sound programmatic media buying decision.
  2. Brand safety: Since this file provides clear information about the sellers, demand sources can make informed decisions about where their ads appear and ensure that their brand safety and credibility are safeguarded.
  3. Revenue protection: This file helps publishers protect their revenue since it helps demand sources buy from authentic sellers and prevents unauthorized parties from entering the programmatic space.
  4. Ad fraud prevention: Since this file prevents the bad actors from joining the bidding process, it helps prevent ad fraud with ease.

Difference between Sellers.json and ads.txt

Both Sellers.json and ads.txt aim to increase transparency and were both introduced by IAB but, there are some key distinctions between them.

  • Sellers.json: It is aimed to give transparency to advertisers. It is hosted on the SSP and helps establish a two-way relationship between the demand and supply sources.
  • Ads.txt: It is primarily aimed at publishers. It is hosted on the publisher's domain and has a list of authorized sellers. It allows publishers to declare who is authorized to sell their inventory in the digital advertising space.

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