Clients find ticket system somewhat disturbing...so some offer Telephone support and messenger support. The idea really is putting yourself in their shoes..customers tend to panic at any instance (I dont blame them though)...and they often post 3 tickets within a gap of 10 minutes just to try to say "HELP!HELP!"...again I dont blame them, but its not good. In case of an emergency offering a telephone and messenger support line really gives them a bit more calm knowing if they are still stressed they can call...so I'd say a mix of all is required for a steady relationship.

Regards