Robert East presents evidence on successful advertising campaigns where the brand benefits from more sales and higher prices, and he describes how good advertising can sometimes reduce the cost of doing business. The question of repeated exposure is examined: do sales initially gather pace with additional ad exposures, or do the gains get less and less after the first exposure? New evidence on this issue is assessed. The focus then moves to a model of ad response that covers the evidence on repeated ad exposure and explains how advertising may work over both short-term and long-term periods. The processes that could produce the long-term effect are discussed and new evidence is presented on the function of word of mouth. There is a chapter on the psychological processes that are used to explain ad effect and brief sections on the point of purchase and online advertising.