When a promotion week ruins your baseline

Sellers often compare “this month” to “last month” and call the difference a strategy win. In marketplace seller performance analytics, that habit collapses the moment a lightning deal or coupon week sits inside one of the periods.

We shade promotion windows on every traffic and conversion poster. The shaded band is not decoration; it tells the briefing which days must be excluded from a baseline or treated as their own mini-period.

If your export lacks a clean promotion flag, keep a simple operations calendar: deal name, start, end, and SKUs included. Ten minutes of calendar discipline saves an hour of false conclusions on the call.

A Monthly Seller Briefing that ignores promotions will eventually recommend fixes for problems that were only temporary price theatre.