Google AI Max is replacing Performance Max for shopping. Standard Shopping campaigns still exist. Here is when to use each.
Precise brand control: Standard Shopping campaigns allow exact control over which products show for which queries via negative keywords and product group bidding. If you have specific brand protection requirements or need to prevent ads for competitor brand terms, Standard Shopping gives more control than AI Max.
Small catalogs (<500 products): AI Max's machine learning benefits from feed diversity. For small, specialized catalogs, manual product group bidding in Standard Shopping may outperform AI Max.