The CAC Tax is the invisible surcharge on every acquisition when your product specs don't match what the market demands. You spend $32 to drive a shopper to a PDP listing a jar-packaged Vitamin C serum — while 65% of top competitors ship airless pumps. 40% of reviews in your price tier request Ceramides and Centella. You offer neither. No creative test, audience swap, or media buyer hire fixes a bottleneck that lives in the formulation and the packaging.

Your hero serum converts 25% below category benchmarks — not because of pricing or checkout UX, but because the specs are structurally wrong. 23% of negative serum reviews cite oxidation or jar degradation. That's a packaging failure, not a formula problem.

Meanwhile, Naturium ships stabilized L-Ascorbic Acid in airless dispensers at $18. Your jar looks obsolete. The tax compounds on every click, every Klaviyo flow, every impression — $1.02M/yr.