What is a private marketplace (PMP)?
A private marketplace (PMP) is an invite-only programmatic auction where a publisher, or a group of publishers, offers specific ad inventory to a selected set of buyers. Access is granted through a Deal ID that the buyer targets in its DSP. Bidding happens in real time, but only invited buyers can compete, usually above a floor price.
PMPs are common for premium publishers, video and CTV inventory, and curated packages built around a topic or audience.
How a private marketplace works
Setup: the publisher or curator defines the package: which sites or apps, which formats, any audience data, and a floor price.
Invitation: through its SSP, the publisher creates a deal and sends the Deal ID to the buyer's DSP seat.
Activation: the buyer accepts the deal and attaches it to a line item with bids, targeting and creatives.
Auction: when a matching impression is available, the SSP sends a bid request that includes the Deal ID. Invited buyers bid, and the highest bid above the floor wins.
Because it is still an auction, there is no guaranteed volume or fixed price. The buyer only pays for impressions it wins.
When a deal does not deliver, the usual causes are bids below the floor, targeting that is too narrow, or a setup mismatch such as an unsupported creative size or a Deal ID not attached to the line item. Checking deal reports in the first days of a campaign saves a lot of lost delivery.
Why private marketplaces matter
Quality: buyers know which publishers and placements they are buying, which cuts exposure to fraud and unsafe content.
Access: some premium inventory is only offered through deals, not the open exchange.
Data: publishers can attach their own first-party audience or contextual data to the deal.
Flexibility: unlike direct buys, there is no fixed commitment, so budgets can move as performance changes.
Common uses include buying premium news or lifestyle publishers for brand campaigns, accessing quality video and CTV supply, and using curated deals that bundle inventory from many sites around one audience or context.
The tradeoff is price and scale. Floors are higher than typical open auction prices, and a single PMP may deliver limited volume, so buyers often combine several deals.
PMP vs open auction
An open auction is open to any buyer with access to the exchange. A PMP restricts who can bid. Open auctions win on reach and cost, PMPs on transparency and quality. PMPs also differ from preferred deals, which give one buyer a fixed price and first look without an auction, and from programmatic guaranteed, which reserves a fixed volume at a fixed price.
Private marketplaces with AdGeeks
AdGeeks runs PMP deals through DV360, Amazon DSP and Adform. Our traders set up the deals you want to access, bid to clear floors without overpaying, and compare deal performance with open auction buying so budget goes where it works best.
