To a media planner, two indices are important –BDI and CDI. BDI indicates sales of a brand as a percentage of population.

BDI= Percentage of brand’s total all India sales/ Percentage of total population x 100

This index enables a media planner to allocate the media budget by setting his priorities.

CDI measures the sales potential of a product category. It takes into account the potential of all competitors selling the same category.

CDI= Percentage of product category total all India sales / Percentage of total population x 100

When both the BDI and CDI are high, we have to spend more on media to maintain them. If there is low BDI and CDI, we have to see why our brand fares poor and devise competitive strategies.If BDI is high, but CDI is low, we have to examine advertising initially, and question whether it will do any good.