Microsoft Advertising expanded its Optimization experiments feature beyond Search campaigns on September 24, 2026, adding support for Performance Max, Shopping, and Audience campaigns. The tool lets advertisers test a campaign change and measure the results before rolling it out account-wide.
Experiments now run for four to eight weeks, and advertisers choose a confidence level of 80, 85, 90, or 95 percent for the traffic split. Microsoft also added scaled treatment metrics for splits that are not divided evenly, so results stay comparable even when the test and control groups receive different shares of traffic.
Eligibility still has limits. Campaigns running on shared or lifetime budgets are excluded, as are any campaigns that include Dynamic Search Ads, so advertisers managing those setups cannot yet use the expanded experiment types. Advertisers start a new test from Campaigns, then Experiments, then Create, selecting Optimization and the relevant campaign type.
PPC News Feed reported the expansion, crediting Hana Kobzová with spotting the change. Teams running Performance Max should treat this as a reliable way to isolate the impact of a single account change, something the campaign type’s heavy automation has made difficult to measure directly.
Per a PPC News Feed report published September 24, 2026.
