The advent of the Internet and e-commerce has brought a new way of marketing and selling many products, including books. The systemwide effects of this retailing shift on costs and the environment are still unclear. Although reductions in inventories and returns provide significant environmental savings, some major concerns of the new e-commerce business models are the energy and packaging materials used by the logistics networks for product fulfillment and delivery. This study analyzes the different logistics networks and assesses the environmental and cost effects of different delivery systems. The definition of analysis system boundaries determines the overall assessment of economic and environmental effects of e-commerce for book retailing. With a return (remainder) rate of 35% for best-selling books, e-commerce logistics costs less and has fewer environmental effects, especially if private automobile travel for shopping is included. Excluding the need to return books, costs and environmental effects are comparable for the two delivery methods.