Sellers.json is an IAB initiative aimed at bringing even greater transparency to each advertising opportunity. It allows buyers to map publisher/seller IDs to the human readable name of the seller making inventory available during the course of an auction.
The sellers.json spec proposes that demand partners fetch a new list at least once a week. There’s only a few hundred files available in total, it probably is best to get a new file at least once per day.
The above image is taken from our previous research on sellers.json persistence, which can be measured by asking: “how much of today’s file is made up of seller objects featured in yesterday’s file?”
What we’ve found is that there is usually a very small diff between the current day’s file, and the previous day’s.
The files are 99% similar on average, based on a sample 225 ad systems which had >=100 seller objects in their file per-day over a 2 week period.
Sellers.json and the SupplyChain object are meant to bring increased transparency to ad buyers, but there is always a risk that someone has implemented them in a way which draws suspicion.
Keeping historical Sellers.json records allows you to identify & close de-authorized supply paths, or find ad systems who may have broken or malicious ad-ops practices.
The Removed Sellers.json Dataset
DeepSee fetches all known sellers.json files each day, and does a diff check with the files available the previous day. This allows us to provide you all the seller objects which are removed or modified each day.
Blocking transactions to de-authorized publishers is one way to protect your ad spend.
We hope that providing this data for free makes it easier for organizations of all sizes to trade inventory more safely.
In the table, we provide each component of a seller object as a column; you will likely be matching our data to your data using the ad system & seller_id columns.
If the seller_id_persists_flag = 0, then this seller_id no longer appears in the sellers.json file at all. Future opportunities which match these ad system / seller_id combos should likely be passed on.
If the seller_id_persists_flag = 1, then this seller_id DOES appear, but one of the supporting columns has changed since the last time we checked. In these cases, we provide the newly updated seller object related to that seller id in the most_recent_seller_id_info json object. This can be parsed & used to replace the existing data you have for a given ad system / seller_id.
If you only need cases where a seller is completely removed, query the dataset where seller_id_persists_flag = 0.
It’s easy & free to get access! Just click here to fill out the access request form, and we will send you an e-mail with instructions on how to locate the data-set.
The data is refreshed each day at 21:00 UTC.
Feel free to reach out with any questions via our chat-bot, or by e-mail at firstname.lastname@example.org