Dan McCarthy spends his time figuring out what loyalty is worth to shareholders, and how to measure it. As cofounder of Theta Equity Partners and assistant professor of marketing at Emory University’s Goizueta Business School, he and his colleague, Wharton professor Peter Fader, have developed a technique called customer-based corporate valuation that helps shareholders value a company by analyzing how its customers behave. Their approach signals a shift from a “growth at all costs” mindset toward sustainable growth based on the acquisition and retention of profitable customers.