For many years I have encouraged my clients to "share your knowledge" as an effective form of marketing. Tell people what you know - demonstrate your expertise - and they will be more likely to remember you when they need your services or products.
That approach to marketing is more prevalent and more effective than ever, thanks in large part to the explosion of more direct channels of distribution. Years ago the "sharing" was done on a limited basis, through articles that we managed to get published, white papers and newsletters. Now my clients share what they know through blogs, on Facebook, with self-published e-books, via e-mail blasts - there are ten times as many options today.
Still, some are still reluctant to "give away the store" by providing too much information for free. They are afraid that, by anticipating and answering questions and offering problem-solving solutions, they will obviate the need for a prospective client to hire them.
Nonsense! Sharing what you know is simply proof of expertise in advance. It allows a potential customer a glimpse into how you think, and what your area (or areas) of expertise might be. Consider this "show and tell" as an audition that could lead to a starring role.