How do I measure incrementality on Display advertising
Incrementality of incremental contribution of Display advertising using audience holdouts, serving the held out audience a PSA ad, and comparing the measured response rate of the held-out audience versus campaign audience.
This process is called Design of Experiments (DoE). When expertly designed has the ability to deliver on the promise of incrementality at the vendor, campaign and audience level in a way that MMM cannot due to practical limits on data granularity and degrees of freedom. For heavily biased tactics like retargeting, DoE incrementality results can be actively incorporated into MMM as Bayesian Priors to improve MMM models across the board. For retargeting tactics, DoE offers the most unbiased measurement approach, as it randomly selects a subset of website visitors for exclusion from retargeting impressions, both in total and at the vendor level, in order to measure true incrementality of these tactics on a customer group that has already established interest and intent. For prospecting tactics, DoE carefully selects a subset of prospects to serve as the control group, showing them a PSA advertisement usually for a charity of the marketers choice in order to determine the true incrementality of impressions. Because this is designed at the group level, DoEs are not subject to all of the user level data challenges encountered by MTA requiring only that campaigns exhibit enough reach to establish statistical significance at the group level. For most advertisers this statistical significance is achieved in a matter of weeks, and can be meaningfully updated afterwards on a weekly basis and be used to inform tactical campaign optimization at the weekly level.