You have 50,000 impressions on TikTok and 3,000 on LinkedIn. Obvious which is winning, right? Not until you know what each one earned. RPM — revenue per 1,000 impressions — is how you find out.
The formula
RPM = (revenue ÷ impressions) × 1,000. If a platform drove $60 on 3,000 impressions, its RPM is $20. If another drove $50 on 50,000, its RPM is $1. The small one is 20× more valuable per view.
Why it changes decisions
RPM stops big, cheap reach from fooling you. It tells you where your attention pays off, so you can double down on the high-RPM platform instead of chasing raw impressions on the low one. To compute it you need revenue per platform — which is exactly the number seenpaid produces automatically.