Selling Live Before It Airs: IAB Tech Lab's LEAP Forecasting API Explained

February was a reminder of why live events matter so much in streaming advertising. The Winter Olympics and the Super Bowl drew enormous live audiences to connected TV screens, and advertisers pay a premium for that kind of simultaneous attention. The problem is that most programmatic infrastructure was not designed for it. Live inventory arrives in unpredictable bursts, ad breaks are not known exactly in advance, and buyers struggle to plan for impressions that do not exist until the moment they happen.

On February 19, the IAB Tech Lab opened public comment on a proposal to address the planning side of that problem: the Live Event Ad Playbook (LEAP) Forecasting API. Comments are open through March 20.

What LEAP is

LEAP is an IAB Tech Lab initiative focused on live-event advertising in streaming. Its first phase produced the Concurrent Streams API, which helps buyers and platforms understand the scale of a live opportunity in real time, meaning how many viewers are watching right now.

The Forecasting API is phase two. It moves earlier in the process. Instead of telling buyers how big an audience is at the moment of the break, it lets content owners publish structured information about upcoming programming ahead of time, including:

• Event schedules
• Expected ad breaks
• Viewership forecasts

That information would flow from broadcasters and content owners to exchanges and DSPs using a shared schema aligned with existing OpenRTB and AdCOM standards. The Tech Lab describes the goal as enabling standardized discovery of upcoming programming, including but not limited to live events, so that buyers can plan, create deals and reserve inventory. Supporters quoted in the announcement included Disney and The Trade Desk.

Why this matters

Live inventory is often sold too late or too cheaply

If buyers cannot see what is coming, they cannot plan budgets around it. The result is that a lot of live streaming inventory either sells through direct deals negotiated weeks in advance, which favors the largest broadcasters, or ends up in the open auction at the last moment, where it competes with everything else and may not reach the buyers who would value it most.

Surges break auctions

When a big moment in a game triggers a break for millions of concurrent viewers at once, ad decisioning systems have to handle a massive, simultaneous burst of requests. Buyers who have not planned for the volume run out of budget or cannot respond in time. Advance forecasts give DSPs a chance to prepare pacing and budgets for known peaks.

Smaller live content owners get a way to be discovered

The biggest sports rights holders already have sales teams that sell live inventory directly. A standard way to publish schedules and forecasts could help smaller streamers, such as regional sports networks, college and minor league streams, local news broadcasts and esports tournaments, make their live inventory visible to programmatic buyers without a large sales operation.

What sellers should consider

Forecast accuracy becomes a reputation issue

Publishing viewership forecasts to buyers means being held to them. Forecasts that consistently overstate audiences will make buyers discount future forecasts. If you are a content owner, start comparing your internal forecasts to actual concurrent viewers now, event by event, so you know how reliable they are before you share them.

Ad break structure needs discipline

Expected breaks are only useful if they are reasonably predictable. Live sports have natural break points, while other live formats may not. Work with production teams on consistent break structures and clear signaling, such as accurate SCTE markers, so what you publish matches what airs.

Think about what you share and with whom

Schedules and forecasts are commercially sensitive. Consider which partners should receive them and in what detail. A standard makes sharing easier, which is precisely why sharing policies need to be decided deliberately.

Deals and floors for live moments

Advance visibility makes it practical to create deals tied to specific events. Plan pricing that reflects the value of live attention, and do not let premium live breaks fall into the same floor rules as on-demand library content.

What gaming and esports publishers should take from this

Esports and gaming live streams share many of the dynamics of traditional sports: scheduled events, predictable peaks at key matches, and highly engaged audiences that advertisers value. They also tend to be underrepresented in programmatic planning because buyers lack a standard way to see what is coming. If you operate live gaming content, this proposal is worth reading closely and commenting on, since the spec is being shaped now.

What to do this month

1. Read the proposal on the LEAP standards page and share it with whoever owns streaming ad operations.
2. Ask your SSP and ad server partners whether they plan to support the Concurrent Streams and Forecasting APIs.
3. Audit your forecasting accuracy for recent live events.
4. Review how ad breaks are signaled in your streams.
5. Submit comments by March 20 if you have operational concerns.

The takeaway

The proposal is still in public comment, and details will change before anything is final. Adoption will also take time, since content owners, exchanges and buyers all need to implement it before the value shows up in pricing.

Live events are the best inventory in streaming, and they are also the most operationally demanding. The LEAP Forecasting API is an attempt to make that inventory visible and plannable before it airs. For content owners who invest in reliable forecasts and consistent break structures, that visibility should translate into better demand and better prices. For everyone else, it is a clear signal of where buyers' expectations are heading.