For the configuration of key values in GAM, does Opti Yield need normal key values or do they need to be custom dimensions?

Opti Yield requires both normal key values and custom dimensions.

Opti Yield requires both normal key values and custom dimensions. All key values are needed to enrich the data for better segmentation, to define the optimized group and control group and to set all floor prices. 

Opti Yield uses only one value per custom dimension. This means that we do not multiply custom dimensions and then consume the budget available for custom dimensions.