If You Had Your Own Computer Troubleshooting Centre

Hello everyone!
I am starting a new computer service center, and im looking for active ideas to make my pc repair unit more customer friendly as well as to provide high tech support..and of course..increase the rep and net profit of my pc repair unit.

If you had your own computer service unit, what methods would you have had employed to push up the sales? tell us, what innovative methods would you have had adopted to be at the top?..what else tricks you would have applied?

As a customer now, what do you expect from a good pc troubleshooting unit?
what methods you want the repair guys should take to make you feel comfortable while dealing with that repair unit?

What do you like and dislike about the current service centers that are there (or any that you have availed)

Waiting for your reply guys