Kill the ROAS Crutch: Build a Profit Stack

For years, ROAS (Return on Ad Spend) was the go-to metric for performance marketers. It was simple, clear, and instantly gratifying — the higher, the better. But as Mark Deruyter points out in our latest episode of The MarTech Matrix, that once-reliable metric has quietly become one of the most misleading KPIs in modern marketing. We cover: The Problem with ROAS The Better Stack: MER, CAC, and LTV Measuring What Matters How AI Is Changing the Game Speed, Fit, and Impact: A New Way to Buy Tech Takeaways ROAS is overrated. It relies on platform data and third-party cookies, which makes it unreliable in today’s privacy-first world. It measures spend efficiency, not profitability, and can create a false sense of success. Shift to MER, CAC, and LTV. Trust first-party data. Platform dashboards are directional only. Real insight comes from CRM and transaction data that connect spend directly to sales and retention. Retention is AI’s next frontier. AI can now identify inactive customers, predict churn, and trigger personalized outreach automatically. Retention automation is becoming the biggest growth lever for established brands. The modern marketer’s must-have skills: Buy technology based on speed, fit, and impact. If a tool can’t be implemented and delivering results within 30 days, it’s probably not the right one. Focus on solutions that make your team faster and smarter, not bloated with features. Collaboration beats silos. The best marketing teams align brand, creative, and performance to connect storytelling with measurable growth. Bottom line: Move beyond vanity metrics. Build a profit stack grounded in first-party data, AI, and metrics that matter — MER, CAC, and LTV. The future belongs to marketers who measure what actually drives profit, not just performance. Chapters 01:27 How the marketer’s job changed (real-time, cross-team) 06:30 Brand’s rising importance & authenticity 09:02 Gut vs data (keep the art, validate the inputs) 12:36 Tools that accelerate marketplace performance (Stackline, Helium 10) 14:21 First-party truth over platform dashboards 15:32 Overrated metrics: ROAS → shift to MER, CAC, LTV 17:46 How to think about LTV at earlier-stage brands 21:32 Buying tech: 30-day implementation mindset; time-to-value 24:31 What vendors miss (research, economics, CFO proof) 30:42 AI’s impact: compress data → creative → execution 32:07 Acquisition vs retention (why retention wins next) 35:10 Future skills: data fluency, AI literacy, brand authenticity 38:23 Underrated channels: Affiliate & SEO (and AEO) 40:53 BFCM tip: have backup copy/creative variants ready