Open auction vs PMP vs preferred deal vs programmatic guaranteed

People say “programmatic” as if it were one product. In practice a buyer can reach the same publisher four different ways. The labels — open auction, PMP, preferred deal, and programmatic guaranteed — describe how closed the door is, and how certain the outcome is.

If you remember only one line: open auction is a public sale, a PMP is an invitation, a preferred deal is a fixed price with first look, and programmatic guaranteed is a reserved buy that still traffics through pipes.

Open auction

The open auction, also called the open marketplace or open exchange, is available to any eligible buyer connected to that SSP. There is no deal ID. The highest valid bid above the floor wins. The publisher does not promise a volume.

Use it when you need reach, retargeting scale, or a low cost per thousand. The tradeoff is control. Inventory quality varies, more intermediaries can sit on the path, and brand-safety work happens with block lists, ads.txt checks, and supply-path rules rather than a named relationship.

Private marketplace (PMP)

A private marketplace is an invite-only auction. The publisher, or an SSP packaging that publisher, creates a deal ID and shares it with selected buyers. Those buyers bid against each other. Everyone else is outside the room.

You still might not spend the budget. If no invited buyer clears the price, the impression can fall through to the open auction or go unfilled, depending on how the publisher set priority. PMPs are how buyers ask for a known set of sites, apps, or CTV channels without reserving every impression in advance.

Preferred deal

A preferred deal keeps the invitation and replaces the auction price with a fixed CPM. The buyer gets a first look. If the buyer passes, the impression can be offered to other demand.

Publishers like preferred deals when they want a price they already agreed, without promising that every requested impression will be delivered. Buyers like them when a specific environment is worth a known number, and they do not want to win an auction against themselves.

Programmatic guaranteed

Programmatic guaranteed is the closest thing to a traditional insertion order that still runs through ad tech. Buyer and seller agree on price, volume, and flight dates. The publisher reserves the inventory. The campaign still uses tags, OpenRTB, or a deal ID so trafficking, creative checks, and reporting stay automated.

Choose it when the plan fails if the impressions do not run: a product launch, a sponsorship, or a must-hit reach number on a named publisher.

Side-by-side

• Who can bid — Open: eligible buyers. PMP, preferred, and programmatic guaranteed: invited buyers.
• Price — Open and PMP: auction. Preferred and programmatic guaranteed: fixed CPM.
• Delivery promise — Only programmatic guaranteed reserves impressions.
• Scale — Open is widest. Guaranteed is narrowest and most predictable.
• Typical job — Open: reach. PMP: curated pools. Preferred: price certainty. Guaranteed: reserved delivery.

How priority usually works

On a single impression the publisher’s ad server often asks in this order: sponsorships and programmatic guaranteed first, then preferred deals, then private auction, then the open auction. A high open-auction bid does not jump a guaranteed campaign that already reserved the slot.

That order is a business rule, not a law of OpenRTB. If your deal “never delivers,” check whether a higher-priority line is taking the same ad break, and whether the buyer’s DSP is actually bidding on the deal ID.

Which type should you pick?

• Need as many cheap, eligible impressions as possible — start with the open auction, then add path and quality filters.
• Need a named set of publishers and can tolerate some under-delivery — use a PMP.
• Already know the CPM and want first look — use a preferred deal.
• Need the impressions to run — use programmatic guaranteed, and confirm the publisher can reserve that volume.

FAQ

Is a PMP the same as a programmatic guaranteed deal?

No. Both can use a deal ID. A PMP is still an auction and can under-deliver. Programmatic guaranteed fixes price and volume.

Can one placement use more than one type?

Yes. Publishers commonly reserve a share as guaranteed, offer a preferred price to a few buyers, and let the rest clear in a PMP or the open auction.

Where do I see the deal in OpenRTB?

Private and guaranteed opportunities are passed in the pmp object, with a deal ID, a floor or fixed price, and the auction type the buyer should use.

← All posts · What is a PMP? · Supply path optimization · Demand partners