Geo - A set of locations
Test Geo - The set of locations where we will implement a spend change for the duration of the experiment.
Synthetic Control Geo - These are weighted conversions in the control group. We use this to simulate the experiment and determine the probability of significant results.
Lift - The incremental effect of the spend change in the test geo.
Approximate CPA - this is a reasonable guess at the spend required to acquire a customer in the channel of interest. This is used to calculate the total spend required in the experiment to produce the number of conversions required for statistical significance in the test geo. A higher CPA means that you will need to spend more to drive the conversion.
Experiment length - The number of days during which we will implement the spend change in the test geo.
Bias - The simulated difference between the actual incrementality and the effect estimated by the experiment analysis.