This is a really cool Excel calculator for tracking the average return on investment (ROI) and the Internal Rate of Return (IRR) per a given marketing spend. The nice thing about adding in IRR is that it takes time into account for a better analysis on the timing aspect of the returns.
The model can be used for any business that has a marketing / advertising spend and then direct revenues related to that spend that happen in the same month or over time or both.
The model is driven from monthly cohorts. The user enters their marketing spend for each month (downwards) and then the revenue generated from that spend to the right of each spend month cohort. Up to 131 months of time can be tracked at once.
A final total ROI and IRR are also derived from a consolidated view of all months based on the spend month and return on that month’s spend over time as well as the average number of months it takes to pay back the initial spend.
To make it easier to understand, each row of the file is the performance of a single month. It will have the initial spend in the first box and then the revenue directly related to that spend in each future month. As you go down in rows, the revenue data entry will start further and further to the right.
There are advanced formulas used in order to get the proper timing of cash in/out on the periods.
A final metric will show the average number of months it takes to recover the initial ad spend for each month and in aggregate. It is possible the spend never gets recovered if future revenue generated from a given month is less than the marketing investment.