Printing Resources originally took any printing business that walked in the door. When they realized which kinds of customers they worked with best, they were able to cut down their marketing costs and make more money. Some computer consulting firms only work with one customer per industry so they will have no conflicts of interest. You can bet they select customers carefully, and that customers are flattered by the partnership approach. It will help you focus, and may impress the right customers if you share it with them.
Word of mouth is the least expensive, most effective way to get new business.
Barry Farber has new customers write on the back of their business cards why they bought. These become mini-testimonials. Bob Brassard calls at least one client a day just to keep in touch. This builds the relationship by showing he doesn't just care about them when he wants something, allows him to update files, and generates referrals. One upscale dentist put up a Web page.