Just a quick tip...
Everyone knows customer support should be swift, helpful and informative. In fact, informative to the extent that you're solving their problem and relating it to selling other products.
For example, I had a customer open a support ticket asking if they could receive a discount on installing a website I was selling. An inexperienced business person might just say, "Sorry, the price is $27" and close the ticket.
An experienced business person would answer, "Installation discounts are available at 3 sites and another deeper discount at 5 sites. Would you rather own 3 or 5 cashflow sites?"
The customer purchased two more sites to get the 3 site installation discount. Voila! Tripled my sales with Customer Support.