Concepts, Characteristics and models of b2b ec Types of Transactions spot buying The purchase of goods and services as they are needed, usually at prevailing market prices strategic systematic sourcing Purchases involving long-term contracts that usually are based on private negotiations between sellers and buyers Electronic Commerc Prentice Hall 2006Electronic Commerce Prentice Hall © 2006 10 Concepts, Characteristics, and Models of B2B EC – Types of Transactions spot buying The purchase of goods and services as they are needed, usually at prevailing market prices strategic systematic sourcing Purchases involving long-term contracts that usually are based on private negotiations between sellers and buyers