Microsoft Advertising has expanded Optimization experiments to include Shopping, Audience, and Performance Max campaigns, previously limited to Search campaigns only. This update simplifies the process for advertisers to test and evaluate campaign adjustments.
Advertisers can now plan experiments lasting 4 to 8 weeks, allocate traffic using a confidence level selector with options for 80%, 85%, 90%, and 95% confidence, and see scaled treatment metrics for non-50/50 splits. However, campaigns with shared or lifetime budgets, or those with Dynamic Search Ads, are not eligible.
Advertisers can begin the experiment creation by navigating to Campaigns > Experiments > Create, selecting Optimization, and then choosing the campaign type.
Read the official announcement here spotted by Hana Kobzová: Create and manage an Optimization experiment.