Method and assumptions
MER compares total business revenue with advertising spend. Unlike attributed ROAS, it includes organic and repeat revenue, so the two metrics should not be treated as substitutes.
MER = total revenue / total advertising spend. Contribution after ads = revenue - COGS - fulfillment - other variable costs - advertising.
Common questions
Why can MER improve while campaign ROAS falls?
Organic or repeat revenue may rise even when attributed campaign efficiency declines.
Should fixed overhead be included?
This contribution view excludes fixed overhead. Add it under other costs when you need a fuller operating view.
Independent calculator. Not affiliated with or endorsed by the platforms mentioned.