The issue is forecasting revenues. Zoom in and the issue is forecasting unit sales. Zoom in and the issue is forecasting new unit sales. In the example, this line does a lot of the work in the model: "Forecasting New Subscriptions (line 10). We've just entered hardcodes here for simplicity, but these could be the result of calculations related to a marketing / sales funnel" I submit that this single assumption will c…
Edit: For existing businesses this metric is much more predictable by the way, but especially in B2B it might be obfuscated because the finance department does not know how much value has been provided for which there was not an invoice created for it yet.