Appointment-Plus makes a great add-on service for your call center clients. When customers of your clients call in, you can book their appointments directly into the system. Your client would then receive an e-mail notification and be able to access their appointments at any time.
It's a great selling point for your current and prospective clients. They'll love the feature-packed system and your reps will quickly and easily be able to book appointments for call-in customers.
Appointment-Plus also comes with a control panel for call centers allowing them to quickly access accounts.