Ad size is a reporting dimension that refers to the size of an ad associated with an impression (for example, 200 x 800). Here's what you need to know about how ad size is interpreted in reporting:
- Ad size is logged for each bid response sent to a publisher. This becomes part of the bid data that's made available in reporting.
- The PubMatic system supports multi-bid responses from DSPs. Each non-zero bid in a multi-bid response is counted individually.
- For bid requests that are not filled, PubMatic reporting shows the ad size as 'unknown'. This example is the Ad Size Performance report:
How does multi-bid work?
PubMatic supports multi-bid responses from DSPs. This means when a DSP responds with a bid, instead of responding with the single best bid, the DSP responds with multiple competitive bids. PubMatic then evaluates these bids against publisher filters and other competitive bids before selecting the winner. The end result is a more efficient and accurate marketplace, which drives higher value for both buyer and seller.
Here are two scenarios:
PubMatic's Multi-Bid Scenario: DSP-X brings its $5 bid as well as its second best bid from a different advertiser at $4. DPS-X’s $5 bid is still blocked, but the SSP is able to see that it has another. In this case, instead of losing the impression as in the single-bid scenario, DSP-X wins the impression for its client.
Single-Bid Scenario: DSP-X brings its best bid of a $5, while DSP-Y brings its best bid of $3. In this scenario, DSP-X’s $5 bid is automatically blocked by the publisher’s rule on URLs (and typically, the DSP is unaware of why it lost the bid). DSP-Y wins the auction at $3.