Loyalty may not be the first idea that pops into your head when you think about electronic commerce. After all, what relevance could such a quaint, old-fashioned notion hold for a world in which customers defect at the click of a mouse and impersonal shopping bots scour databases for ever better deals? What good is a small-town virtue amid the faceless anonymity of the Internet’s global marketplace? Loyalty must be on a fast track toward extinction, right?