Love seeing this SlideShare from Wil Reynolds after being asked to model Click through rates and ROI for years by dozens of People. There are far too many variables to reliably come near 30% accuracy – then comes the additional time and change variables.

I’ve learned that there is an equally small chance of convincing those requesting these models to abandon their requirement for them as the request inevitably comes from the top. It is however, still futile to produce them.