Best practice
Breakeven MER: the one number to set before you scale ad spend
Most brands scale ads against a benchmark someone else invented. The only return target that means anything is the one computed from your own margins — here is the arithmetic.
Before any account is scaled, one number has to exist: the return at which an order stops losing money. Not a platform benchmark, not a category average from a webinar — a figure computed from the brand's own unit economics. We set this in week one of every engagement, and it reframes every decision that follows.
The arithmetic
Take contribution margin: what is left from a rupee of revenue after the cost of goods, shipping, payment fees and packaging. Breakeven MER is simply its inverse:
Breakeven MER = 1 ÷ contribution margin
- A brand keeping 50% of each rupee breaks even at 2.0×.
- A brand keeping 40% breaks even at 2.5×.
- A brand keeping 30% — common where COGS runs near 70% — breaks even around 3.3×.
That last case is why benchmarks are dangerous: plenty of 'good' dashboards show a 3× return that is quietly underwater for a high-COGS brand. We have audited accounts where the platform celebrated a return the margins could not survive.
Three refinements that matter
- Use real costs, not the spreadsheet from the pitch deck. Shipping subsidies, COD failure rates, returns and marketplace fees all live inside contribution margin. If margin is unverified, say so on the tracker and treat the breakeven as provisional — an honest asterisk beats a confident fiction.
- Recompute for sale windows. A sitewide discount cuts the margin, which raises the breakeven — at exactly the moment the return looks spectacular. Judge sale weeks against the sale-price breakeven, not the evergreen one.
- Separate new from returning where you can. A first order at breakeven can still be a good trade if reorders are real. But that is a deliberate payback-period decision with a date on it, not a permanent excuse for missing the floor.
Running on the floor
Once the floor exists, the monthly conversation changes shape. Above breakeven with room to spare: scale, and watch whether the floor holds as spend rises. Hovering at breakeven: fix the inputs — creative, offer, product mix — before adding budget, because scale amplifies whatever economics you already have. Below it: cut, no matter what the platform dashboard claims it caused.
How that return gets measured honestly — store revenue over total spend, never platform-attributed revenue — is its own discipline, covered in MER vs platform ROAS.