JustPremium this month announced it has implemented Sellers.json and the OpenRTB SupplyChain Object in all outgoing bid requests. JustPremium says advertisers will not need to worry anymore about fraudulent traffic, nor about vendors reselling impressions to duplicate them and drive up costs.
JustPremium says it was one of the first to implement the two new SupplyChain tools. SupplyChain Object is a record of each intermediary between the publisher and the advertiser.
Via the SupplyChain Object, the buyer is able to see which sellers and re-sellers have been involved in each bid request.
In August, Index Exchange announced the Sellers.json adoption. Pubmatic, Ströer, AppNexus, Rubicon Project also adopted the sellers.json. Google has not implemented yet the sellers.json.