Many smaller companies just focus on top line revenue and profits.
The problem is that a single product line could cost more than it should and not be profitable even though the company is.
This is especially important if you discount.
You should know, at a high level at least, what your revenue, expense, and profit is by product line.
If you have a product line that is costing money, and you're discounting, it could be a major drag on profits without even knowing it.
The same goes for major customers but I'll leave that for another post.