When you learn of something happening in their field or a related field, clip the newspaper or magazine article and send it. Or maybe a catalog or a new book by a big name in the industry. Send it or the book review. Maybe a program in their area of interest will be broadcast on TV or radio. Give them the time and date.
Problems can be good or bad.
Good if you know about them bad if you do absolutely nothing to help solve the problem. A good listener resolves many a complaint. Enter attempt to solve. Attempt precedes solution because you don't know what the exact problem is at this point. Research the problem and then solve it.