PMP (private marketplace)
A PMP is an invitation-only programmatic auction where selected buyers bid on a publisher's inventory under a deal ID. It sits between the open exchange and guaranteed buys: better quality and transparency than open auction, more flexibility than a fixed commitment, usually at higher CPMs.
In practice
PMPs suit brands that want known, premium environments - news, broadcast, vertical publishers - while retaining auction pricing and audience layering.
Deal IDs need active management: unmonitored PMP deals routinely under-deliver while the open exchange quietly backfills.