No, you shouldn't combine prospecting and retargeting in one PMax campaign. It's a very common question, but merging them ultimately obscures your data and creates a false sense of security about your performance.
The reason is that Performance Max is built to find the cheapest, easiest conversions, and those will almost always come from retargeting or branded search traffic. As Sam Piliero mentioned on the 2X eCommerce Podcast, platforms like Google are incredibly good at capturing conversions that were going to happen anyway. When you mix prospecting and retargeting, PMax will naturally spend your budget on those warmer audiences, inflating your campaign ROAS. This makes it look like the campaign is a huge success, but you have no real way of knowing if it’s successfully acquiring new customers or just taking credit for existing ones. It prevents you from making smart decisions about your ad spend optimization.
The better, and more common, strategy is to split PMax into at least two separate campaigns: one for Brand and one for Non-Brand. On an Ecommerce Playbook episode, Tony Chopp explained this is his most common tactic. This structure allows you to set different targets and budgets for acquiring new customers versus retaining existing ones. It gives you far more control and cleaner data. You can use your Non-Brand campaign for true prospecting, and you can even mine its search term reports for new keywords to target in dedicated search campaigns. It’s a bit more work, but it’s the right way to manage Google Ads for ecommerce.
