EXCLUSIVE: Dan Porter, who led the charge in building William Morris Endeavor’s digital business over the past three years as head of its department, is leaving the agency. He will exit on Nov. 30 to concentrate on his own company and to help grow his sports app, Overtime (which WME was an early investor in). In Porter’s absence, Chris Jacquemin will lead digital content/talent for WME while Beth Ferreira will continue to lead WME Ventures.