Most of the agentic advertising conversation has focused on buyers, but publishers now have their own version: the seller agent. A seller agent works before the auction rather than inside it. It reads a brief, matches it to inventory and books the deal within limits set by the publisher.

The first benefit is a stronger direct sales channel. IAB Australia's explainer on the IAB Tech Lab agentic initiative says the direct negotiation capabilities should "revitalise the direct sales channel" and free up time for improving products and managing client relationships. IAB Tech Lab is also working on a proposed standard, OpenProposal, aimed at the stretch between an advertiser's brief and the moment someone commits money. Anyone who has chased RFP responses will see the appeal.

Vendors are moving fast. Magnite says its seller agent lets publishers create custom inventory and audience packages with flexible pricing and targeting controls, and make inventory discoverable and purchasable by buyer agents. Its president of revenue and market strategy, Sean Buckley, argues the technology works best when "connected to the systems that power the transaction". Closer to home, Maddy Mewing of Magnite told Nine's programmatic team on the Mediaweek Newsmakers podcast that "The big buzzword at the moment is agentic".

PubX has a bold pitch. They launched in Australia this month under country manager Andrew Gilbert and claims 78 cents of every advertising dollar reaches publishers, against a traditional average of 43 cents. Founder Andrew Mole told Mi3 that if an agent can run a campaign talking to another agent, "it doesn't need to use a DSP or an SSP". Gilbert's read on the Australian market is that "Australia has traditionally been a fast follower in adtech". We should treat these numbers as vendor claims for now. For a sense of what agentic demand pays in the auction environment, DataBeat's US data found agentic buyers clearing at a $6.13 CPM against $6.95 for conventional programmatic buyers. That compares two kinds of auction demand rather than guaranteed direct deals, where certainty matters as much as price, but it's a reminder to ask what price agentic demand actually clears at.

Standards and guardrails matter here, and that is where IAB Australia comes in. Its AI Working Group, set up in May 2025, released a vendor-agnostic LLM Prompting Framework in May 2026. IAB Australia's Tech Lab lead, Jonas Jaanimagi, described it as "the connective tissue between strategic human intent and autonomous machine execution". The group will keep reviewing agentic requirements for the local market, and IAB Australia has been running the AAMP reference software in a lab. It is seeking participants for a seller-side sandbox pilot, which would be a low-risk way for publishers to test.