When the buyer is an AI agent, a publisher's floor price should be a written policy rather than a single number: a walk-away price for each product and deal type, the delivery terms that price assumes, and a short list of concessions the seller agent may trade and the ones it may not. Buying agents ask more sellers, more often, in a more comparable format than human buyers do. Any floor that is inconsistent across products, open to unlimited negotiation or detached from quality terms will be found and used. The goal is a floor that a buyer agent can read, a seller agent can enforce and a person can audit afterwards.

TL;DR. A floor price for agent buyers works best as a four-part policy: a list price, a walk-away price, the conditions the price assumes, and the concession rules. Floors should be set per product and per deal type, because buyer agents compare like with like across sellers. A price floor means little if the seller agent can quietly give away measurement or viewability terms to protect it, so price and quality terms should be fixed together. Offers below the walk-away price should go to a named person, not be settled by the agent. Every floor, counter-offer and exception belongs in the deal record both parties hold.

Why do AI buying agents change how floor prices work?

In an open auction, a floor is a reserve price applied to each bid request. The demand-side platform bids above it or does not bid, and nobody negotiates. In an agent-negotiated deal, the floor becomes a negotiating position, and three things change.

The first is comparability. IAB Tech Lab's OpenProposal specification, part of its AAMP framework, standardises how publishers define products and packages and present them in RFP responses, so a buyer agent can compare offers from different sellers in one format. AdCP, the separate protocol from AgenticAdvertising.org, has a get_products task that sends one brief to every connected seller. A publisher's floor now sits next to every comparable offer the agent received.

The second is persistence. An agent does not tire of counter-offers. If a seller agent will drop its price a little each time it is asked, a buyer agent will keep asking.

The third is memory. A buyer agent that keeps its negotiation history can treat a concession granted once as the opening point for the next negotiation. A one-off discount stops being one-off.

What should a floor price policy for agent buyers contain?

The four-part floor is a simple way to make the policy explicit enough for a seller agent to follow:

List price: the price the product is offered at, stated in the product description.
Walk-away price: the lowest price the seller agent may accept without a person signing off.
Conditions: the terms the price assumes, such as placement, format, flight dates, audience definition and the measurement basis.
Concession rules: what the seller agent may exchange for a lower price (a longer flight, a larger volume commitment, wider placement flexibility) and what it may never trade (the measurement basis, brand safety settings, blocked categories).

Most publishers already hold this information, but it tends to live in sales staff's heads and in email threads. A seller agent can only enforce what it has been given in writing.

Should floor prices differ by deal type?

Yes. According to IAB Tech Lab, AAMP's support for the Deals API covers programmatic guaranteed, preferred deals, private marketplaces and the open marketplace. Each deal type gives the buyer something different, so each needs its own floor.

A guaranteed deal commits volume and price in advance. A preferred deal gives the buyer first look at a fixed price without a volume commitment. A private marketplace runs an auction among invited buyers. A single floor across all three ignores what each buyer gives in return.

For example, a hypothetical publisher's finance section might carry a list price of £14 CPM. The illustrative policy could set a walk-away of £11 for a preferred deal, £10 as the floor for a private marketplace, and £9.50 for a guaranteed deal that commits at least two million impressions over four weeks. The numbers matter less than the logic: each lower price is tied to something the buyer gives in return, and the seller agent can explain which.

How do price floors and quality floors interact?

A price floor only means something alongside the terms it buys. If a seller agent can protect its headline price by loosening the viewability commitment, the publisher has moved the discount somewhere less visible.

Buy-side evidence shows how easily quality terms slip in agent negotiation. In Concourse Bench v1, a benchmark of AI buying agents negotiating with software sellers, 95 of the 110 contracts signed promised a viewability floor below 70%. For publishers, the lesson runs the other way: decide the measurement basis and viewability commitment for each product before negotiation starts, and keep both outside the seller agent's authority to change. Where a standard definition exists, such as the MRC's 2014 viewable impression guidelines, the product description should name it.

How should a seller agent handle offers below the floor?

A seller agent facing an offer below list price has four options, and the policy should say which applies when.

Accept when the offer sits between list and walk-away and the conditions match.
Counter with a changed condition, such as a longer flight or a larger commitment, drawn only from the permitted concessions.
Escalate to a named person when the offer falls below walk-away but the buyer is strategically important.
Decline when the offer falls below walk-away and no escalation rule applies.

The escalation route is the one most often left vague. It needs a named approver, a response time and a rule for what happens if nobody answers. An agent that waits indefinitely loses deals. An agent that accepts by default after a timeout has no floor.

How often should floors be reviewed?

Floors set for agent buyers should be reviewed against the record of what agents actually offered, not against the rate card alone. Every accepted, countered, escalated and declined offer is evidence.

If most offers on a product cluster just below its walk-away price, either the floor sits above what the market will pay or the product description is not persuading buyer agents that it is worth more. If almost every offer is accepted at list, the floor may be too low.

That record also protects the floor in a dispute. A deal agreed at £11 with a stated viewability commitment can only be defended if both parties hold the same version of those terms. Alkimi, a neutral agentic advertising marketplace working within IAB Tech Lab's AAMP framework, approaches this through its DealSheet: agreed terms are written at the point of agreement, timestamped and held by both parties, with humans keeping approval rights at the deal level.

Frequently asked questions

What is a floor price in agent-negotiated advertising?

A floor price is the lowest price a publisher's seller agent may accept for a product without human approval. For agent buyers, it works best alongside a list price, the conditions the price assumes, and rules on what the agent may trade.

Should a publisher let its seller agent negotiate below the floor?

No. Offers below the walk-away price should either be declined or escalated to a named person. Letting the agent go below the floor on its own turns the floor into a suggestion.

Do AI buying agents push prices down?

Buyer agents can compare offers across sellers in one format and repeat counter-offers without tiring, which puts pressure on any floor that is inconsistent or loosely enforced.

Should viewability terms be negotiable alongside price?

Publishers are better served fixing the measurement basis and viewability commitment per product before negotiation, so the seller agent cannot protect the headline price by weakening quality terms.

How Should Publishers Set Floor Prices When the Buyer Is an AI Agent?