Abstract: The present disclosure addresses improvements to online advertising, including improvements that verify, validate, or otherwise confirm that online ad impressions and/or online ad views and the like meet the needs of advertisers. In various embodiments, the data describing online ad impressions and/or online ad views is tested to validate or verify that the data satisfies various criteria defined by or for advertisers, such as demographic, brand safety, visibility, geographic or anti-fraud requirements. The present disclosure also describes improvements in measurements and metrics that describe advertising audiences and effectiveness based on the data describing validated online ad impressions.