Stop Ranking Ad Channels by Sessions: Use RPS (Revenue Per Session) Instead

"Google Ads vs. Meta Ads — same budget, which one is more efficient?" I hear this question almost every week from ecommerce operators. Most of them compare by sessions , and that almost always leads to the wrong answer. I made the same mistake myself once. Meta Ads was driving 1.5x the sessions of Google Ads, so I shifted budget. End of month, total revenue was down . The fix was a simple division: revenue ÷ sessions, by channel. The metric is called RPS (Revenue Per Session) , and it's the only