With Black Friday behind us, Cyber Monday upon us, and retail’s make-or-break season in high gear, many of us are interacting more than usual with front-line service employees. And since it’s also HBR’s 90th birthday, some of us are thinking about the articles that have had the greatest impact over the years. What better moment to re-read “Putting the Service-Profit Chain to Work,” which was originally published in 1994 and reprinted as a “classic” in 2008. The article, written by a leading group of service management thinkers (Jim Heskett, Tom Jones, Gary Loveman, Earl Sasser, and Len Schlesinger) is a great example of both the power a management idea can have, and how much work is required for an idea to become reality.