I have some experience in the online gaming market (i.e. the fantasy football sites in my signature) but this is a new ball game for me.
Aside from their own website, which is ranked #1 for all relevant searches, there are dozens of satellite websites which are connected to the main one. The connections are mostly unofficial, as in, blogs, communities etc revolving around what happens on the main site.
Now, my goal is not to take over for them, as their budget dwarfs mine, but I have a site offering quite a few features that theirs doesn't have and, so if I can just make it to the first page of Google for a few relevant searches, I'm convinced I can gradually take over a part of their user base. My site is currently ranked around #40 for the most important search term after 3 months of activity (theirs has been active for several years).
Basically, in terms of Google ranking, I am not looking to compete against them, but against the unofficial sites that host discussions about their site.
I've done some link building from relevant sources, I've paid for sponsored stories within the niche, the SEO on the site itself is very good.
Any tips on competing in such an environment?