Resold Inventory / Demand Partner
Resold inventory is ad space one company buys from a publisher and sells to advertisers, often sourced from a separate demand partner.
Resold inventory is ad space that one company buys from a publisher and then sells onward to advertisers rather than serving its own direct demand. A demand partner is the network or platform that supplies those ads, the source of paying demand that another seller plugs into its inventory. The two terms describe opposite ends of the same arrangement.
How it works#
A publisher or network rarely fills every slot with direct advertisers, so it connects to demand partners that fill the remaining inventory with ads they sourced elsewhere. The host network displays the slot, but the actual ad and the advertiser relationship may belong to the partner. Standards like sellers.json let buyers see whether a seller owns the inventory directly or is reselling on behalf of someone else, an important signal across the Ad Supply Chain.
Why it matters#
Resold inventory is why the advertiser shown in an ad slot is often not who you would expect. MSN Native Ads, for example, surface resold demand routed through Microsoft's marketplace rather than ads sold directly by MSN. For competitive intelligence, recognizing resold paths is essential: the real advertiser, and the real network behind a placement, can be several hops removed from the page you see it on.
Related terms: sellers.json, Ad Supply Chain, and MSN Native Ads.
