LTV:CAC vs MER
LTV:CAC (Lifetime Value to Acquisition Cost Ratio) and MER (Marketing Efficiency Ratio) both come up in business conversations and get confused. Here's the plain-English difference, side by side, so you can use each one with confidence.
The key difference: LTV:CAC refers to lifetime value to acquisition cost ratio, while MER refers to marketing efficiency ratio — they describe different things even when they show up in the same sentence.
LTV:CAC — Lifetime Value to Acquisition Cost Ratio
The ratio of what a customer is worth over their lifetime vs. what it cost to acquire them. Healthy SaaS benchmark is 3:1 or better — anything under 1:1 means you are paying to lose money.
MER — Marketing Efficiency Ratio
Total revenue divided by total marketing spend. Unlike ROAS, MER captures blended performance across every channel — the number a CFO actually trusts.
When to use LTV:CAC
Reach for "LTV:CAC" when the conversation is specifically about lifetime value to acquisition cost ratio. The ratio of what a customer is worth over their lifetime vs. what it cost to acquire them. Healthy SaaS benchmark is 3:1 or better — anything under 1:1 means you are paying to lose money.
When to use MER
Reach for "MER" when the conversation is specifically about marketing efficiency ratio. Total revenue divided by total marketing spend. Unlike ROAS, MER captures blended performance across every channel — the number a CFO actually trusts.
FAQs
What is the difference between LTV:CAC and MER?
LTV:CAC stands for Lifetime Value to Acquisition Cost Ratio — The ratio of what a customer is worth over their lifetime vs. what it cost to acquire them. Healthy SaaS benchmark is 3:1 or better — anything under 1:1 means you are paying to lose money. MER stands for Marketing Efficiency Ratio — Total revenue divided by total marketing spend. Unlike ROAS, MER captures blended performance across every channel — the number a CFO actually trusts.
Are LTV:CAC and MER the same thing?
No. They're often used in the same conversation because they're related, but they describe different concepts. LTV:CAC = Lifetime Value to Acquisition Cost Ratio. MER = Marketing Efficiency Ratio.
When should I use LTV:CAC vs MER?
Use LTV:CAC when you're specifically referring to lifetime value to acquisition cost ratio. Use MER when the topic is marketing efficiency ratio.