This document discusses e-commerce business models and concepts. It outlines 8 key elements of a business model including value proposition, revenue model, market opportunity, competitive environment, competitive advantage, market strategy, organizational development, and management team. It then describes various business-to-consumer and business-to-business e-commerce models such as portals, e-tailers, content providers, transaction brokers, and market creators. It also discusses how e-commerce has changed industry structure by altering the basis of competition, barriers to entry, threat of substitutes, supplier power, and buyer bargaining power.