There are 2 reasons to participate in a Discussion Forum:

First, if you have an idea or question you want to expose to the community, the Discussion Forum is the ideal place to put it forward. Members of the community will answer your questions and comment on your ideas.

Second, if you are interested in forwarding the overall community dialog, you can browse the forum for topics that you would like to discuss, help answer the questions of others and give your take on any new ideas that arise.