Private marketplace DOOH.

What a private marketplace is

A private marketplace, or PMP, is an invite-only programmatic deal. A seller, typically a media owner or a platform selling on its behalf, offers a curated set of inventory to a specific, chosen set of buyers, at an agreed price, instead of opening that same inventory to the full public auction. The buyers still transact through the same programmatic pipes as an open deal, software, reporting, automated delivery, but the pool of who can see and buy the inventory is deliberately narrowed. In digital out-of-home, that usually means a shortlist of premium or well-performing screens set aside for buyers a seller wants a closer relationship with, rather than every screen going to whoever bids highest in the open exchange.

A PMP sits in the middle of a spectrum, not at either end of it. At one end is the open exchange, where any buyer with a connected demand-side platform can bid on available inventory and the highest qualifying bid wins, wide reach, but no certainty about which specific screens carry your ad. At the other end is a programmatic guaranteed deal, where the buyer and seller agree the exact inventory, volume and price up front, and nothing is auctioned at all. A PMP borrows a bit of each: more certainty and curation than the open exchange, but still a market position rather than a locked commitment. The direct vs programmatic guide lays out all three deal types side by side, with the open exchange and programmatic guaranteed compared the same way.

None of the three is inherently better. Reach, certainty and control trade off against each other, and the deal type worth picking is the one that matches whichever of those matters most for the buy in front of you, not a default habit.

Why a seller or buyer uses a PMP

Sellers run a PMP to protect their best inventory and their best relationships. Opening every premium screen to the fully open exchange means the highest bidder wins it, whoever that is, on any given day. A PMP lets a media owner set aside a curated shortlist, at an agreed floor price, for buyers it wants to keep close: an agency with a standing relationship, a category the seller wants more of, or a buyer it trusts to keep the brand-safety bar high on a flagship screen. The floor price is negotiated once, not rebid on every impression, which gives the seller predictable revenue on its best inventory without fully committing it to one guaranteed buyer.

Buyers use a PMP for the same reasons in reverse. You get a first look at curated, often premium inventory before it reaches the open exchange, at a rate you have agreed rather than one set by an auction you cannot see into. You keep more control over brand safety, since the pool of screens is chosen and vetted rather than whatever the open exchange happens to clear, and you avoid bidding against an unknown number of competitors for the same slot. What you do not get is the full certainty of a guaranteed deal: a PMP is still a market position within an agreed band, not a fixed, locked booking, so it suits a buyer who wants curation and a known rate without committing to one exact volume months in advance.

The trade-off is consistent on both sides of the table: a PMP gives up some of the reach of the open exchange and some of the certainty of a guaranteed deal, in exchange for a curated, negotiated middle ground. That is the whole appeal, and the whole limit, of the deal type.

How Blindspot compares

Blindspot works differently from all three programmatic deal types above, by design. It is an open, self-serve, per-play marketplace: every advertiser who logs in sees the same map of 3,000,000+ screens across 50+ countries, and the same real per-play price on each one, from about $0.23 on urban inventory. There is no auction to win, no invitation required, and no curated shortlist hidden from other buyers. You pick the screens, set the hours, and the price you see is the price you pay, self-serve from $40 with no minimum spend.

That means Blindspot, today, is not a private marketplace and does not run a PMP-style curated deal. There is no invite-only tier, no negotiated floor price set apart from the public per-play rate, and no shortlist of screens reserved for chosen buyers, everything on the map is visible and bookable by any advertiser on the same terms. If that changes, this guide will say so directly rather than imply a feature exists before it does. For now, the closest match to a PMP's curation and predictable pricing on Blindspot is simply the platform itself: a transparent per-play price doing the work a negotiated floor would do elsewhere. See the what is a play glossary entry for how that per-play unit is defined and billed, or the programmatic topic hub for the rest of the deal-type guides.