An incrementality test is an A/B test that includes the suppression of eBay ads to a specified portion of your audience for a specific length of time. To gain confidence in your impact to eBay, we measure your incrementality to track whether your shoppers convert into buyers because of your ad.


Partners that do incrementality testing have the highest confidence behind their numbers. Those with high incrementality and elasticity (ability to drive more sales with higher commissions) are top-of-mind for extra spend when budget becomes available.


*Elasticity, marketing budget, and market conditions are other factors besides incrementality that are considered when making pricing decisions.


Test methods and duration


There are several methods we use to successfully measure your incrementality to eBay:


  1. Impression based testing
  2. Location and IP based testing


We will work with you to identify the best method and customize the test setup, taking into account several factors like traffic volume and testing capabilities: 


The duration of the test will depend on the test method, audience size and other factors. It will likely be conducted in a 3-8 week timeframe:


  • 1-2 weeks for a smoke test to confirm ad suppression and to conduct a power analysis, determining test duration
  • 2-6 weeks for the live test


Post test expectations


Once the test is completed, EPN analytics will analyze the test data and put together a readout to be shared with partners. The readout will contain the test results (such as Site GMB/NoRB lift, statistical significance etc.) along with any insights that can be shared with partners for optimization opportunities. This analysis will be completed about 3-4 weeks after the completion of the test and a meeting will be scheduled to review.