Ad platforms allocate budget based on what they see. When the picture is incomplete, every decision they make is off.
30 to 40% of your purchases never reach any ad platform. Your campaigns are making decisions on a fraction of what actually happened. That is not a media problem. It is a data problem.
Duplicated, delayed, or incorrectly structured events reach your platforms, but their systems cannot learn from them. That is where budget drifts toward the wrong campaigns and ROAS becomes a number you cannot explain.
CRM data, offline sales, regional payment completions, it all exists. It just never reaches your ad platforms. Most brands have no idea what that is costing them in targeting quality and wasted spend.