· 6 min read · Protecxo Media Team
Open auction, PMP or programmatic guaranteed: choosing how to buy
The three main programmatic buying methods trade scale, control and certainty in different ways. Here is how to decide which belongs in your plan.
Most programmatic plans use more than one buying method, but the reasons are not always written down. That matters, because each method answers a different question. Open auction asks how much relevant reach a budget can buy. A private marketplace asks which publishers are worth a premium. Programmatic guaranteed asks how to make sure a specific amount of inventory is there when you need it.
Open auction: scale with discipline
In the open auction, inventory is available to any buyer and priced impression by impression through real-time bidding. It offers the widest reach and the most flexibility: budgets can move daily and targeting can be adjusted at any time.
The trade-off is variability. Quality differs widely between sellers, so open-auction buying should come with curated inclusion lists, brand-safety settings and regular placement reviews. Used that way, it is often the efficient backbone of a plan rather than a risk to be avoided.
Private marketplace: access by invitation
A private marketplace (PMP) is an auction a publisher, or a group of publishers, opens to selected buyers through a deal ID. Deals usually carry a floor price and define the inventory included — for example, a site section, a format or an audience the publisher has built.
PMPs suit advertisers who want more predictable environments without committing to fixed volume. Because they remain auctions, there is no guarantee of delivery; a deal that is priced too low or targeted too tightly may simply not spend.
Programmatic guaranteed: certainty at a fixed price
Programmatic guaranteed (PG) is a direct agreement — fixed price, fixed volume, agreed placements — executed through programmatic systems. It brings the reliability of a traditional insertion order together with programmatic targeting, frequency management and consolidated reporting.
PG is valuable around moments that cannot be missed: a launch, a sponsorship or a high-demand season. It is less flexible once agreed, so it works best when the plan, creative and timing are settled.
Putting the mix together
- Start from the objective. Reach and efficiency point toward open auction; environment and brand fit point toward PMPs; guaranteed presence points toward PG.
- Decide what each method is responsible for, and judge it on that — not on a blended average across all three.
- Review deals regularly. A PMP that is not delivering is a pricing or targeting question, not proof that premium inventory does not work.
- Keep frequency rules across methods, so the same person is not reached three times through three different routes.
The right mix changes from campaign to campaign. What should not change is that the reasons are explicit, written into the media plan and checked against results.