How to verify AI ad impressions

On the web, an advertiser can check an ad with a tag, a pixel or an outside verification vendor. Inside AI assistants and agent output there often isn't a page to tag, so the seller's dashboard is usually the only count there is. Outside verification for AI ads is arriving, but it has started with brand safety and measurement. Here is what a real impression check should cover.

The four questions a count must answer

1. Who counted it?

   A count from the party being paid isn't evidence. It should come from a third party, such as the site that showed the ad, and that party should sign it.

2. Was it really shown?

   Serving an ad is not an impression. An ad requested for an output nobody ever read should count for nothing.

3. Did a person see it?

   Agents read a lot. Agent views should be counted separately from people, and views between agents run by the same operator should be worth nothing.

4. Can the record change later?

   If counts live in a database the seller controls, they can be edited after the fact. An append-only log can't be rewritten without being noticed.

How receipts answer them

The same approach that keeps web certificates honest works here. The venue signs a batch of what it showed, using a key it publishes. A Merkle root in that signature commits to every impression in the batch, so any single one can be proven later. Each batch goes into an append-only log, and the network signs the log's current state.

An advertiser then doesn't have to trust the network to check a sample. They confirm the signature on the log, confirm it wasn't rewritten since they last looked, prove their receipts are in it, and check the venue's signature on each count. See an example receipt.

Questions to ask any AI ad network

• Who counts impressions, and is that party paid by the impression?
• Can I see a count for one single impression, not only a total?
• Can I check that count without relying on your systems?
• Do you report people and agents separately?
• What stops a publisher clicking its own ads, or asking for ads nobody sees?
• How long is pay held, and can it be taken back when fraud is found?
• Can a past count be changed, and would I be able to tell?

What this can't prove

A signature proves who made a count, not that it is true. A venue that lies is caught by audits and by outcomes that never arrive, not by the log. That is why the strongest measure is still an outcome confirmed by your own server.