Have you heard about the 80/20 rule?
In order for you to spend 20% of your effort to create 80% of your profit, you need to understand your profitability at the product, client, division or region level, not at the total profitability level.
Total profitability is the common metric out there. However, it is more accurate for any business to analyze your profitability either by product, client, division or region.