Many practitioners quote the sages without a deep enough understanding of what led them to their conclusions. This is part of why we do not practice in our offices what we preach in our choirs. Many who quote Byron Sharp regarding the principle of The Next New Customer did not study the reasoning which led him there, and therefore carry out plans he would not approve. For example, TRA's Ayala Cohen discovered that there is an ROI on households that had not bought the category in a year -- but it appeared to me lower than the Consumer Lifetime Value (CLV) except in the few cases where the targets had been chosen exactly right. In other words, it mostly wasn't worth it to get them.