There is a hierarchy of effects in consumer decision making as Strong (1925), Hall (1926), Lavidge & Steiner (1961), and then Sugiyama & Andree (2011) describe. The fundamental differences between the first three models and AISAS model of Sugiyama & Andree is the linear and nonlinear behavior that consumers show. Please describe what are the differences and how should you implement the AISAS model to internet based communications and viral marketing/word of mouth?