Many service companies rely on skilled, personable employees to satisfy customers, but finding them can be costly; in some industries the annual churn rate exceeds 50%. Weak labor markets and click-to-apply online applications increase the burden on companies, which may get hundreds of applicants for a single opening. Consider the British call center industry: In 2012, 7 million people applied for 260,000 jobs.

A version of this article appeared in the November 2013 issue of Harvard Business Review.