OOPS ? :P
I've 1 biggish support contract ... which has a turn around time of a few hours / 24 hours on issues .. which is quite cool

(rare I'd say as well)
For other customers .. They drop me a mail and I fit them in ... it can't always be a case of giving them priority all the time or I'd end up getting nothing done.
Maybe if I end up expanding the business ... but for the moment its ok
Its kinda like ... what do you do on holidays ? Customers can leave a message and I'll get back to them. For the most part though things work *prays*