A heat map is pretty. But the beauty isn't the point — the decision it forces is. If you look at a heat map and change nothing, you've spent money on decorative wall art.
What it reveals: the hot zones (where attention and footsteps concentrate), the cold zones (where they simply don't go), and the real path people take — which is almost never the one you drew on the floor plan. Add dwell time and you have the map of where your space works and where it sleeps.
And what that changes, concretely: the margin product goes to the hot zone, not to the "logical" spot on the plan. The cold zone stops being ignored and gets a decision attached — it's fixed, changes function, or gets a reason to exist. Staffing goes where the flow is at the right hour. And an anomaly (an aisle that suddenly went cold, an entrance that lost attention) stops going unnoticed for a month.
The honest caveat: the heat map shows the what, not the why. It tells you that corner is cold; it doesn't tell you whether it's the lighting, the signage, the assortment or the window. That's where the retailer's eye comes in. The data narrows the question from "why are sales weak?" to "why does nobody go to this corner?" — which is already a question you can answer and fix.
It doesn't replace the instinct of someone who knows stores. It points the torch.