Profit
Where does the business actually make money?
Not revenue. Profit. And not total profit, margin at the level that matters. By product. By channel. By customer. Most businesses know their overall gross margin. Far fewer know which SKUs are profitable, which channels carry real economics after trade terms and logistics, or which customers are worth serving at the margin they generate.
When profit isn't understood at this level, decisions get made in the dark. Products get scaled that shouldn't be. Channels get invested in that erode economics. Pricing discipline breaks down without anyone noticing until it's already in the numbers.
The profit engine needs to be designed, not reported on.