I was talking to my friend and colleague Lewin Williams yesterday. Lewin is a financial services consultant who helps other financial services consultants improve their business. Lewin’s philosophy—the one that has made a big difference for his clients—is simply this:

Focus on your “A” clients.

Now that sounds simple and obvious, doesn’t it? Focus on the 20% of your clients who bring in 80% of the results. Obvious, right?

Except that it isn’t.

If it were really that obvious, everyone would be doing it, ...