Relative Potencies
The confidence limits table (shown here for probabilities from .25 to .75) displays the promotional value necessary to achieve a desired probability of purchase. For example, a 46.518% off sale would entice 50% of Online customers to make a purchase, while a 57.905% off sale would raise the probability of purchasing to 50% for Catalog customers. The relative median potency of these two sites is the ratio of the promotional values needed to obtain a 50% probability of purchase, or 46.518/57.905=0.803.
The relative median potencies are displayed in a separate table. The first row shows an estimate and confidence interval for the relative median potency of the Online vs. Catalog sites. Since the confidence interval does not include 1, you can conclude there is a difference in their median potencies. Specifically, the Online site is more potent because it requires a smaller promotional value to achieve median potency.
Looking at the rest of the table, you can conclude that the Online site is more potent than the Catalog, which in turn is more potent than In-Store.
Note: the probabilities shown in the confidence limits table and used in the computation of the relative median potencies do not include the natural response rate; thus, these are probabilities conditional upon the customer arriving at the site without the intention of making a purchase.