In some embodiments, a method defines a test group from a population of consumers that have been exposed to a communication associated with a promoted entity. The test group includes a (1) retailer profile, and (2) a first purchase amount associated with the promoted entity. The method also includes receiving purchase information associated with a third party. The purchase information includes (1) a second purchase amount associated with the promoted entity, and (2) a third purchase amount associated with the promoted entity. The method further includes defining a first multiplier based on a relationship between the first purchase amount and the second purchase amount, and defining a second multiplier based on a relationship between the first purchase amount and the third purchase amount. The method additionally includes sending a signal indicative of a combined multiplier based on (1) the first multiplier, and (2) the second multiplier.