Click to view a price quote on PAYX. Click to research the Diversified Services industry. : Billionaire activist Bill Ackman on Tuesday evening defended a blockbuster campaign he has underway at Automated Data Processing (ADP)  , arguing during an hour-long call intended to reach the payroll firm's large retail investor base that the company's corporate headquarters and U.S. offices should be integrated. "The opportunity here is relatively straightforward," Ackman said on a webcast. "Restructure the organization, reduce its complexity, redesign the incentives, make it focused more on the clients, reduce bureaucracy and consolidate the footprint of the real estate."