Firstly here is my simple excel table on how the revenue numbers was generated that I mentioned in the Graffiti Presentation. One can debate about the numbers and estimations but that is the beauty of having a financial model. A model breaks down assumptions and helps you reach a reasonable value for each of the assumptions thus creating a suitable range of values that you will receive.

One should focus on getting a reasonable output range of values instead of just specific values because there is too much uncertainty in defining specific values. Plus in this case, what is important is how the 4 sources compared relative to each other.