The Clients' Guide includes two-page profiles of the world's largest public relations firms, with each firm evaluation of criteria ranging from talent to intellectual leadership. It also contains reviews of more than 150 small and midsize firms in niches from crisis management to high-technology public relations.

Each review is designed to provide potential clients and prospective employees with insight into the firm's recent performance, specific areas of strength and weakness, and culture, and is compiled based on information provided by the firm itself, interviews with clients, and feedback from industry opinion leaders.