Speed is critical. Customers expect a 24 hour response time. They are delighted by hearing from you within 6 hours and amazed by a 1 hour response. The faster you respond to your customers the easier it becomes to close a sale or solve a problem. Failure to return a call or email is inexcusable. When responding to a customer complaint always begin by assuring the customer that you will fix their problem. This immediately removes the adversarial relationship that can lead to messy and expensive confrontations.