The general assumption is that QA forums (usenet groups, mailing lists, web forums, etc) provide a service for people who have questions that require answers. My view is that the *real* value of these forums, in fact, is that they provide a service for people who like to *answer* questions (for whatever reason).
Well ... that might be taking it a little too far. Let's just say that "it works both ways" ...
I *do* know that I've learnt much more from answering questions, than I have from asking questions :-)