Pull ROAS for the same week from Meta, Google, and TikTok, and you'll get three different stories about how well your ads are performing. Meta says 5.2x. Google says 3.8x. TikTok says 6.1x. None of them are lying, exactly, but none of them are telling you the whole truth either. If you're trying to figure out how to compare ROAS across Meta, Google, and TikTok in one report, the real work isn't pulling the numbers. It's making them mean the same thing before you compare them.