InstagramCurrencies
Revenue in one currency and spend in another gives a ratio with no meaning. Convert both to one currency, using a stated rate and date, before dividing.
Time zones
A store may close its day at midnight in one time zone while an ad account closes in another. Daily numbers shift, and month ends can move orders into the wrong month. Align every source to the same zone.
Refunds and cancellations
Decide whether revenue is gross or net of refunds, and apply the same rule to every period. Mixing the two makes the trend look better or worse than it was.
Taxes and shipping
Some platforms report purchase value including tax and shipping while the store reports net sales. Compare like with like.
Spend that is missing
Add all channels: a forgotten platform makes MER look better than it is.
Write it down
Put the definition, the period and the currency next to the figure. If a source was unavailable for a day, mark that day 'not measured' instead of using zero.
