[How to] Calculate ROI/Profitability of Paid Traffic (e.g. PPC)

Intro:

I've just been discussing this with an affiliate of mine and thought it'd be an interest to others; so I decided to do a quick post. It is about how to calculate ROI/profit from paid traffic (such as ppc) and how to estimate profitability of a product you are considering promoting. I'll also throw in some info about how to optimize ROI.

Calculating ROI/Predicting profitability

Let's say you are running a PPC campaign, where you are driving traffic to a…

[How to] Calculate ROI/Profitability of Paid Traffic (e.g. PPC)