What Is Programmatic Advertising? How It Works in 2026, From Display to AI Conversations

Programmatic advertising is the automated buying and selling of ad placements through software, usually in a real-time auction that clears in the time it takes a page, a video or an AI answer to load. It is how most digital advertising is now transacted: the IAB and PwC report that US digital ad revenue reached nearly $300 billion in 2025, and that the programmatic share of it grew faster than the whole.

This guide explains how programmatic works, who the players are, what the deal types mean and what it costs, then covers the newest inventory it has absorbed: ads inside AI conversations. Where we stand: Thrad is a demand-side platform for that last category, so the final section is ours and the rest is the industry's.

What is programmatic advertising?

Programmatic advertising replaces the manual version of media buying, in which a salesperson and a buyer agree a price and an insertion order for a block of impressions, with software that buys impressions one at a time against rules the advertiser sets. Amazon Ads puts the definition at its simplest: "Programmatic advertising is the use of advertising technology to buy and sell digital ads." The technology decides, for each impression, whether to bid, how much, and which creative to show.

The scale is the reason to understand it. The IAB/PwC Internet Advertising Revenue Report for 2025 says "the digital advertising industry reached nearly $300 billion in revenue in 2025, the highest level in the report's history," and coverage of the report puts programmatic revenue at $162.4 billion, up 20.5 percent year over year, which is more than half of the total.

How does programmatic advertising work?

The core mechanism is real-time bidding (RTB). IAB Tech Lab, which maintains the OpenRTB protocol that most of the industry uses, describes it this way: "Real-time Bidding (RTB) is a way transacting media that allows an individual ad impression to be put up for bid," and "this is done through a programmatic on-the-spot auction, which is similar to how financial markets operate." The current specification, OpenRTB 2.6, was released in September 2023. In practice, one impression goes through six steps:

1. A person opens a page, app, stream or conversation that has an ad slot.
2. The publisher's supply-side platform sends a bid request describing the slot and whatever it knows about the context.
3. Demand-side platforms (DSPs) representing advertisers evaluate the request against each campaign's targeting and budget.
4. Each DSP that wants the impression returns a bid and a creative.
5. The exchange runs the auction and picks a winner.
6. The winning ad is served, and both sides log the result. The whole round trip takes milliseconds.

What are the programmatic deal types?

Not every programmatic buy is an open auction. Four deal types cover most of the market, and the choice decides how much control and how much price certainty you get:

Amazon Ads describes the last one plainly: "Programmatic guaranteed advertising promises a certain amount of impressions for your ads." The further down the table you go, the closer programmatic gets to the direct buy it replaced, with automation keeping the execution.

Which channels are bought programmatically?

• Display: banners and native units on websites and in apps, the original programmatic channel.
• Video and connected TV: in-stream and streaming-TV inventory, now one of the fastest-growing segments.
• Audio: streaming music and podcasts.
• Digital out-of-home: screens in public places, bought by time and location.
• Retail and commerce media: placements on retailer sites and apps, tied to shopping data.
• AI conversations: placements inside AI assistants and AI apps, the newest channel and the one covered below.

What does programmatic advertising cost?

Programmatic is priced per thousand impressions (CPM), per click (CPC) or, less often, per action, and the price is set by auction rather than a rate card. Three things move it: how many advertisers want the same impression, how valuable the context is, and how well the creative performs, since most auctions weight relevance. Auction design matters too. OpenAI, for example, documents a "relevance-weighted, second-price auction" for its placements, with recommended starting CPC bids of $3 to $5. Ask any seller which auction type they run and what fees sit between your bid and the publisher's payout.

What are the benefits and the problems?

• Benefits: one buy reaches many publishers; budgets move in real time toward what works; every impression is logged; and targeting can use context and data no sales call could.
• Problems: a chain of intermediaries each taking a fee; fraud and low-quality inventory in open auctions; brand-safety risk when you cannot see the page; and the learning curve of a DSP.

The standard answers are to prefer private marketplaces and guaranteed deals for premium inventory, use verification, and demand log-level reporting from the DSP.

What changes when AI enters programmatic?

AI touches programmatic in three places, and our AI programmatic advertising guide covers each in depth:

• AI inside the stack: bidding, pacing, audience prediction and creative generation are now machine-learned in every major DSP.
• Agents as buyers and sellers: IAB Tech Lab's 2026 Agentic Roadmap extends OpenRTB and the existing standards so that software agents can negotiate and execute buys.
• AI conversations as inventory: the newest supply. The bid request describes a conversation rather than a page, the decision is made while the assistant is answering, and the placement appears inside or beside the answer, labeled as sponsored.

That third change is where Thrad sits. Thrad is a DSP for ads inside AI conversations: advertisers bid on conversational intent in real time, with delivery in under 500 milliseconds, across 20+ countries, with one budget and one report across every AI app. Conversational inventory is bought the way the rest of programmatic is bought; what changes is the signal underneath it, not the unit you pay in. Launch a campaign from self-serve, or read how programmatic buying for the AI era works. Our AI advertising platform guide maps every seller of this inventory.

How do you start with programmatic advertising?

1. Set one goal per campaign: reach, traffic or conversions. It decides the pricing model and the deal type.
2. Choose a DSP by the inventory you need, not the feature list: display and CTV, retail media, or AI conversations.
3. Start in open auction with tight targeting, then move proven inventory into private or guaranteed deals.
4. Instrument measurement before launch: pixels or server-side events, and a report you can join to your own analytics.
5. Review fees and auction type with every seller, and ask for log-level data.