The numbers speak for themselves. Are you ready to bring the Challenger selling model to your organization? by Free Sales & Marketing Magazines and Downloads from verticalinsider.tradepub.com / 0 Comment / Posted in: Marketing With over 80,000 sellers and 20,000 managers improving their sales results based on the Challenger™ selling model, and more than 461,000 books inspiring change around the world, we’re just getting started. Are you ready to join us? Request Free!