A Private Marketplace (PMP) is an invitation-only programmatic auction where a publisher — or a curated group of publishers — makes premium inventory available to a select set of advertisers at agreed floor prices. Sits between two endpoints: open-exchange RTB (anyone can bid, lowest prices, lowest quality control) and direct guaranteed deals (negotiated upfront, fixed price, no auction). PMPs combine the efficiency of programmatic with the curation of direct deals.
When PMPs make sense
- Publishers with premium inventory who want programmatic efficiency but won't accept the open-exchange race-to-the-bottom pricing. They invite specific advertisers.
- Advertisers in brand-sensitive categories (luxury, finance, healthcare) who need brand-safety guarantees the open exchange can't provide.
- Cross-channel buys (CTV + display + mobile) where unified inventory access matters more than absolute lowest CPM.
How PMPs work mechanically: the publisher creates a "deal ID" in their SSP and shares it with invited advertisers. Advertisers configure their DSPs to bid into that deal ID. The auction runs like a regular RTB auction, but only invited DSPs can participate, and the floor price is negotiated upfront.
PMP vs Programmatic Guaranteed: PMP still runs an auction (you might not win if you bid below floor); Programmatic Guaranteed locks in a fixed price + volume commitment upfront. PMP is more flexible; PG is more reliable for advertisers needing committed volume.
Programmatic deal types compared
| Deal type | Auction? | Pricing | Best for |
|---|---|---|---|
| Open exchange (RTB) | Yes, open | Lowest | Reach, scale, low CPM |
| Private Marketplace (PMP) | Yes, invite-only | 2-3× open floor | Premium inventory + brand safety |
| Programmatic Guaranteed | No | Fixed, upfront | Committed volume + reliability |
PMP sits between the open exchange and direct guaranteed deals — programmatic efficiency with curated, brand-safe inventory at a negotiated floor.