eBusiness pros to date have overlooked an invaluable source of customer insights: payments data. We surmise that they've hesitated because payments data is inherently sensitive, and they worry about breaching customer trust. Handled the right way, however, transaction data closes the loop between customer insights and loyalty data and gives merchants a full view of all their customers. This report analyzes how retailers are integrating payments data into common customer insight practices and explains how payments data drives greater intimacy with customers.