Many consumer markets display complex behavior, meaning that traditional forecasting models perform at a level that excludes practical use, for instance when predicting the market shares of new products or the effects of marketing strategies. Interaction among consumers, comprising normative influences and word-of-mouth, is one of the key processes behind this complex market behavior. The papers in this JBR Special Issue adopt a complexity approach in analyzing and managing consumer markets. This approach focuses on a general problem that is highly relevant to marketing and market dynamics: how one can describe, understand, predict and manage complex consumer markets. (C) 2007 Elsevier Inc. All rights reserved.