This interesting post from the Cialdini camp about error management suggests that making an error and then fixing it may give you customers for life. They cite a hotel where the 2 childrens' sized tennis racquets were in use, so a staff member drove to a sports store and bought 2 more: the guest was so impressed they booked the family in for another holiday.
It's an example of customising the service ad hoc, where being perfect up front isn't as good as making things fit the client.
And of course where letting the client know that we customised is just as important as the customisation.
So if you customise to your client, are you remembering to let them know (e.g. do you mention on your bill that you didn't charge for the phone meeting or the extra trips to site? do you send them a "nil" bill for free services rendered?). How are you making sure they know what you have done to adjust and make it work for them?

