Spend mix: this chart shows the share of total spend by media channel. It provides a view of the actual average media mix in the dataset used for training.

Attribution %: this chart shows the share of the KPI, i.e. dependent variable, that is attributable to a specific media channel. The mean baseline at the bottom shows the share of the KPI that is attributable to all other non-media variables, i.e. other independent variables, seasonality, trend, etc. This is arguably the share of the outcome we'd see if all media spend was set to zero.

ROI: return on investment is defined as the ratio of the outcome attributed to a specific media channel by its related media spend. It is therefore defined as outcome (KPI) units per dollar spent. To get a true ROI you may need to multiply this ratio by the average value per outcome unit, e.g. customer lifetime value or revenue per unit.