Good luck with that!
Most people expect to sign up and start using us like their own personal Google or Twitter. And then they disappear without so much as a thanks. It is the way of the Internet generation. Research, reading, applying some effort, is not how they do it. They type a couple keywords, hit enter, and expect a vast quantity of relevant and factual data to be delivered in milliseconds, instantly make them an expert on the topic... The concept of an "Internet community" is lost on them.
On another forum I am a member of, if a new thread is started regarding an old topic, the members will simply flag it and might respond with suggested searches or threads to look at. The mods will then either merge the thread with an existing one, or delete the thread within 24 hours. I thought it rather harsh at first, but not anymore. Searching that forum is a joy, with usually only 10 or 12 threads bring returned, and almost always offering the info desired.