Today's increasingly complex media environment means once-reliable marketing performance measurement techniques, such as marketing mix and attribution models, fail to properly credit marketing tactics with customer actions or influence. B2C marketers must embrace a new measurement standard — unified measurement — that will measure marketing's entire value and identify the best ways to optimize customer interactions. This is an update of a previously published report; Forrester reviews and updates it periodically for continued relevance and accuracy. We revised this edition to factor in new data and ideas.