I've just added a forum to my site in a folder, e.g. www.domain.com/forum and I'm wondering whether posting new threads or simply posts would count as updating the site and therefore adding new content. Anyone know ?
Definately, if you search Google (say for here for example ) you will find loads of indexed pages, all different. Therefore they are treated as new content/pages. So with this in mind it is important to create many posts using the keywords your site is aimed at, so when searches are made you stand a chance of being found.
Definately counts as content updates and will look great for the search engines. You should add a blog, which is much easier to update and add information
yes of course because the robots will found additional pages on your site, so that is considered an update.