Hi,
The Ad Performance Report document states that the report "includes all statistics aggregated at the ad level, one row per ad". It also states "This is a single attribution report when CriterionId is requested".
I have been issuing requests using only Attributes - ie. no segmentation or metrics, but am still seeing many cases of multiple rows for one ad - when I request CriterionId in the report, I get the exact same report back, but with the addition of the keyword_id (CriterionId) for all rows. It seems like at the moment, there is no non-segmented version of this report. Is this behavior expected?