It has been true for a long time that brokers, realtors, and even demographers have considered only a very narrow number of factors in determining practice site viability. Traditionally, this may have been due to a misunderstanding of how to interpret the available data. We knew, for example, if the population surrounding a practice site was growing or shrinking. We certainly could tell if the competition around a location was increasing relative to the population. Terrific! But the science of demographic analysis has grown and deepened while the users of these numbers have not kept up. And there is little surprise why this is so: it is heavy lifting!