Margin

Margin

n. The profit made from selling an ITEM after accounting for all overhead expenses like shipping, labor, and other costs.

NOTE: The higher an ITEM'S Margin, the more profitable it is for the STORE. Couple that with high TURNOVER on the SHELF and you have A Very Good Thing.

My hunch is that if you also consider rate of TURNOVER and other factors, bottled water may be the most profitable thing in the STORE.