It stopped surprising me years ago when a new client (who had previously hired a different attorney) would exclaim, "I never knew that. My attorney never explained that to me." I have come to realize that the number one complaint clients have about their lawyers is that the lawyer never communicates with them. The lawyer does not answer the client's calls and never informs them of the underlying needs and criteria of a successful case. Many of these clients, who may have signficant cases, ultimately fire the first lawyer and hire one who spends the time to communicate with them.
First, it is common courtesy to respond in kind when someone asks for your input. Second, attorneys have an ethical obligation to keep their clients informed. Next, as the attorney, you should want your clients to know what it is going to take to successfully prosecute their case so you can manage their expectations and protect them from the potential pitfalls of not taking your advice and heeding your guidance. Finally, regular calls to your clients will keep you informed and provide you with the most important tool and attorney has in his briefcase - information. If you don't actively seek out relevant information from your client you may be missing out on facts that result in significant developments in their case.
A client who is informed and made to feel comfortable, educated and cared for becomes a pleasure to work with and will sing songs of praise for you by recommending you as the attorney who always answers their questions and let's them know what is going on with their case.