Sometimes a deal will call for a large and complex financial model to understand the inner-workings of a business and all the interconnected variables. But a lot of times the most important thing you can do is what some people refer to as "back-of-the-envelope" math. What has to be true for this to be a great outcome?

You're evaluating an early stage business that builds software for contact centers. The closest comparable company in the public markets is Five9 ($FIVN). You need to build a model to "dream the dream" in terms of what is reasonable for how big this early stage business could become.