Michael Porter didn't get to be a giant in the field of competition and strategy by hunting small game." Joan Magretta begins her new book on Harvard Business School's Michael Porter's work by noting that, from the start of his career, Porter has been asking a big question when it comes to understanding everything from the free enterprise system to the individual motivations of managers. Why are some companies more profitable than others?

Most retailers are at a very basic level in how they use loyalty programs, and many customers see loyalty programs as punitive," says Harvard Business School senior lecturer José Alvarez. "Loyalty schemes are not being used to their best advantage." Fortunately, there's hope. Retailers that do rewards programs right can see "incredible loyalty," says Alvarez. In the case note Customer Loyalty Schemes in the Retail Sector, Alvarez and coauthor Aldo Sesia, a research associate at HBS, discuss how loyalty schemes evolved, what they look like today, why so many retailers aren't using them effectively, and how they can be improved to win customer business in an uncertain marketplace

Are people who travel in town cars and on corporate jets different—on a psychological level—from you and me? Does the availability of luxury goods "prime" individuals to be less concerned about or considerate toward others? The answer from new research seems to be yes.

About 95 percent of new products fail in the marketplace. The problem, in part, is that most companies segment their markets according to product category or customer demographics, neither of which is very effective. Products are more likely to succeed if companies segment their markets according to "jobs-to-be-done"--addressing the basic problem a customer is facing and providing a product that can deliver the necessary result. Each job has functional, emotional, and social dimensions. Companies can also apply the jobs-to-be-done approach to product branding. A "purpose brand" clearly reflects the job that a product does, such as Kodak's FunSaver brand of single-use cameras, which performs the "job" of preserving good memories.