Which really is the same thing as social media. :)

First of all, what does your forum offer? If it's a computer forum, for example, check out computer sites and start acquainting yourself with the community. Then tell them that you have a forum and...

I also can't completely agree with stymiee. HTML sitemaps help users, but they also help the Googlebot which crawls your site to get to those deeper pages.

XML sitemaps help the search engines...

What kind of sitemaps? Are you talking about the HTML file or the XML file that is read by Google itself?

Either way, it helps -- it ensures that your content is being spidered or at least that...

Actually, no, SEO is about optimizing your site, but it's a subset of SEM (search engine marketing) which includes anything from link building to social media efforts and everything in between.
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