The book _How to Become a Successful Consultant in Your Own Field_ by
Hubert Bermont was recommended at a recent lactation conference.  From
page 172:

"* We are paid for advice given, not advice taken.

*  We can only be running streams of expertise.  We can force no client
to drink from that stream.

* The most difficult concept for a client to accept is change: and change
is what the consultant is retained to accomplish.

*  Fifty percent of all clients take the advice they pay for.  Of that,
only 50 poercent of the advice is implemented.  So consequence can only
result from 25 percent of the consultant's total endeavor."

Terriann Shell
Big Lake, Alaska