MER / blended ROAS
Honest top-line efficiency; resists attribution gaming.
- Formula
- Total revenue / total ad spend (all channels)
- Unit
- ratio
- Models
- E-commerce
| E-commerce | 3×–5× | Triple Whale |
| E-commerce | 6×+ | Triple Whale |
| E-commerce | (good 2.4×) | Triple Whale |
What it is
Marketing Efficiency Ratio (MER), also called blended ROAS, is total revenue divided by total ad spend across all channels for a given period. Unlike channel ROAS, it makes no attribution assumptions — every dollar of revenue and every dollar of spend is counted regardless of which platform claims credit.
How to calculate it
Sum all revenue for the period (ideally net of returns), then divide by the total paid media spend across all channels (search, social, display, streaming, etc.) in the same period. The result is a ratio expressed as Nx.
Why it matters
MER is the sanity-check metric that anchors channel-level ROAS claims to reality. When platform-reported ROAS numbers add up to more revenue than the business actually generated, MER exposes the discrepancy. It is especially useful for ecommerce brands running multi-channel campaigns where attribution overlap inflates individual channel figures.
Benchmarks & pitfalls
Triple Whale data (2025–26): healthy DTC businesses run MER of ~3–5x; mature subscription ecommerce businesses run >6x. The 2025 Triple Whale customer median was only ~2.4x, indicating many brands are operating below healthy thresholds. MER is directionally useful but has no built-in cost structure — a 3x MER on a 20% gross margin business is very different from a 3x MER on a 60% gross margin business. Always interpret MER alongside gross margin before drawing conclusions about profitability.