Performance Max campaigns are a relatively new campaign type that allows for the targeting of multiple placements, using multiple inventory types. 


Its reason for existing is to supplement Search campaigns by providing greater conversion volumes across GDN, YouTube, Discover, YouTube, and Gmail, while also generating keyword suggestions for Search campaigns.  The impact is to strengthen Google campaigns by having image, text, video and catalog assets work in parallel to generate revenues.


Performance Max is, effectively, the next logical step in the development of Machine-Learning-based campaigns. It combines increased integration of asset types, more advanced insights, and a shift to a more holistic form of conversion reporting.