In sequential presentation of product information, determining which form of presentation is better and why is theoretically important (Klink and Smith 2001), and holds implications for communication of product value through advertising, packaging, brand extension, and brand alliances. This research proposes and tests a novel affect-based mechanism for product evaluation under ordered presentation. In this mechanism, affect not only mediates the impact of ordered presentation on willingness to pay (WTP), but does so by determining whether heuristic or systematic processing is employed.