And how can you make this statement? How can you use all of that wonderful business school education and determine ROI in the NFL? The owners have not once stated a number for their profits. That seems to be a critical number to calculate ROI. In fact, gross income numbers aren't used to calculate ROI so the one number we know for sure isn't useful to determine ROI. Just looking at the values of the franchises you can see how much owners will make on the sale of their teams without looking at yearly profit/loss.
I am a CPA and I can't tell you the ROI for the owners without looking at the books.