I was doing some reading, and came across some great articles on Net Operating Income. NOI is an important gauge of a company’s ability to generate profit from its core business. While it’s only one piece of the puzzle when analyzing companies, understanding it can help you compare two firms who may have the same Net Income (Profit) but drastically different core businesses. Have a look if you can:

Zooming in on Net Operating Income. Investopedia
A Clear Look At EBITDA. Ben McClure. Investopedia