Most forums have social network share buttons, so members can share, tweet and like any forum discussion. I can see some SEO value in doing this, not only for the forum, but for forum users with signature links leading to their own blog or website. A lively discussion could attract interest in some social networks, and the discussion might get shared again, or retweeted. Even if the discussion only has an opening post, it could attract more people to the forum, and that will improve the value of links in posts and signature links, where these are allowed. Each forum post has its own link, so it is also possible to link any forum post in a tweet or an update, and to share the post in social bookmarking networks. Do you think this is an effective way to get more traffic to your own site, or as a way of promoting a forum?