Private marketplace

An invite-only variation of the RTB model.

While an auction is still conducted, just a handful of advertisers participate, bidding against one another to buy a publisher’s inventory (typically premium).

This is in stark contrast to the typical open and public RTB auction.

With PMP, advertisers reserve, or guarantee, their ads before the publisher offers them on the public RTB marketplace.

Further reading:

• Understanding RTB, Programmatic Direct and Private Marketplace
• The AdTech Book by Clearcode: 09. Media-Buying Methods: Programmatic, Real-Time Bidding (RTB), Header Bidding, and PMP