The study of relationships, networks, and interactions in food and agriculture business-to-business marketing and purchasing is an important endeavor. From having been concerned with getting the "marketing mix" right, the food and agriculture setting has experienced significant changes over the past decades. Traditionally, marketing focused on attracting new customers in a broad market, or a specific segment, against a background of unfulfilled demand, thereby satisfying growing demand by using marketing techniques, portfolio analysis, and production means. This approach to marketing is, therefore, likely to be less effective since its focus is on attracting new customers. An alternative approach to marketing emphasizes the value of maintaining customers to grow profits and sales. In food and agriculture business-to-business marketing and purchasing, the maintenance and enhancement of relationships, networks, and interactions ("relationship marketing") with different stakeholders is as important as the attraction of relationships, networks, and interactions ("transaction marketing"). Yet, the story of how relationship marketing fits into the greater marketing landscape has been somewhat inconsistent. Also, a lack of empirical work underpins the conceptual development in food and agriculture of relationship marketing, which often is characterized more by rhetoric than by publication effort on empirical findings. This e-book seeks to address some of these research lacunae in the literature.