Are your best clients those who have been with you the longest?  Apart from the fact that your longest-term clients may be paying your lowest rates, just because someone has been with you since 19xx doesn’t mean that they are your best client — or even that they love/appreciate/tolerate the work you do for them.  In a post talking about a long-term client’s dissatisfaction with (perceived) higher billings, Jeffrey Phillips hits the nail on the head and shares six lessons his company learned from the episode:

We perceive that we work in the best interests of our clients, often redirecting or turning down work that we think is unnecessary for the client - or attempting to find good, lower cost alternatives.  However, doing this doesn't necessarily mean the client recognizes those efforts as beneficial to them.  I've learned a few things:

• never assume that because a relationship is long that it is necessarily a good one
• never assume that silence means that a customer is happy
• have the data to support your positioning that you are doing things for the good of the client
• toot your own horn to the client ocassionally.  No one else does.
• recheck your assumptions and value proposition periodically.  What a customer valued a year or two ago may not be so important now
• keep the customers that value the benefits you provide, and fire the customers who can't establish a trusted relationship with you.

The first two should be written on top of every file, don’t you think?