There is a growing problem in the professional services industry that is often acknowledged but rarely discussed openly: clients--even long-standing ones--are much less loyal to firms and partners than they once were. This dramatic shift in client behavior has rendered traditional approaches to business development not only ineffective but counterproductive. But top performers have figured out a radical new approach that is redefining what it means to be a "rainmaker" in today's professional services market. Drawing on a comprehensive, quantitative study of nearly 3,000 partners, The Activator Advantage identifies the five types of partners found across the professional services landscape and shows how only one of them--the Activator--drives consistent growth. Activators deeply embed business development habits into their daily workflow, aggressively leverage their internal and external networks, and proactively deliver both business and personal value to clients. Packed with eye-opening data, counterintuitive insights, and robust case examples, The Activator Advantage provides the road map for any professional services partner or firm leader looking to chart a path to greater client engagement, internal collaboration, revenue growth, and firm profitability in the new era of client disloyalty.