sellers.json

IAB standard for SSPs to declare seller relationships A working definition from the RGM marketing glossary.

Schematic — sellers.json

IAB standard for SSPs to declare seller relationships

Term: sellers.json
Field: Programmatic
Category: Programmatic

A working definition

Here is the short version.Treat sellers.json as an auction-based concept with a clear scope. Two people using the term should mean the same thing.

IAB standard for SSPs to declare seller relationships

Programmatic refers to automated buying and selling of digital advertising using software, exchanges, and real-time bidding. The ecosystem includes DSPs, SSPs, ad exchanges, data providers, and verification vendors.

sellers.json sits in Programmatic; it is an auction-based concept. Define it once and the reporting holds together.

The mechanics

Worth a slow read.There is no single setting for sellers.json. It bends to the audience, the channels, and the wider plan.

sellers.json behaves unlike a fixed rule. An early-stage brand and a mature one will apply sellers.json on different terms. The mechanics follow the inputs around it. Treat sellers.json as a buzzword and the reporting misleads; agree on it and the numbers hold.

One rule always holds. Settle the scope of sellers.json up front, then build the plan. Get it backwards and sellers.json becomes a word everyone uses and no one shares. Worth a slow read.

When teams use it

Here is the short version.sellers.json earns attention at three moments: setting budget, choosing a metric, comparing options. Away from those, it waits.

Bring sellers.json in when a live choice hangs on it. In programmatic work, that usually means one of three moments. Away from a decision, sellers.json is background, not a lever.

Setting budget. sellers.json signals which line earns the marginal spend.
Choosing a metric. sellers.json separates a causal read from a coincidence.
Comparing options. sellers.json evens out a comparison that would otherwise mislead.

A concrete walk-through

Look at it this way.Below, sellers.json is put inside a Instacart setting -- real trade-offs, a clear baseline, and a figure to test it.

Take Instacart. During a sponsored-product audit, the team made sellers.json the deciding input, not an afterthought. They set a baseline first, agreed one definition of sellers.json, and only then read the result: 20% of spend moved to higher-incrementality SKUs. The number matters less than the order.

Worked example for sellers.json -- illustrative figures, RGM analysis
Stage	What the team did	The reason
Baseline	Logged where sellers.json stood before the test.	A fixed point of truth.
Define	Fixed one meaning of sellers.json for the test.	Two people, one meaning.
Act	A sponsored-product audit — one variable.	Cause and effect, isolated.
Result	20% of spend moved to higher-incrementality SKUs	An outcome you can trust.

These sellers.json numbers are illustrative -- RGM analysis. The structure travels; the specific figures do not.

Failure modes to watch

Worth a slow read.Four failure modes recur with sellers.json. Name them and they are easy to design around.

One-size thinking. Using sellers.json flat across every segment. The right cut differs by channel and margin.
No context. Reporting sellers.json with no baseline. A bare number cannot be judged.
Chasing the word. Optimizing sellers.json for its own sake. Check it tracks a real outcome.
Bad compares. Benchmarking sellers.json with no adjustment. Account for the model differences first.

Frequently asked questions

What is sellers.json?

IAB standard for SSPs to declare seller relationships Settle what sellers.json covers first; the strategy follows from there.

Why does sellers.json matter?

sellers.json earns its place when it shapes a real decision. The leverage is in correct use, not in the word itself.

How do teams use sellers.json?

Teams put sellers.json to work on a spend split, a metric, or a head-to-head call. See the Instacart walk-through above.

What is the most common mistake with sellers.json?

Treating sellers.json as one blanket rule and reporting it with no baseline. Both hide a soft assumption.

What is sellers.json?: IAB standard for SSPs to declare seller relationships Settle what sellers.json covers first; the strategy follows from there.
Why does sellers.json matter?: sellers.json earns its place when it shapes a real decision. The leverage is in correct use, not in the word itself.
How do teams use sellers.json?: Teams put sellers.json to work on a spend split, a metric, or a head-to-head call. See the Instacart walk-through above.