When i first get to your site, i think Nice skin, but what the hell is this forum about? Replace the stanard welcome header message with something that as a little more shine and information to it. Include brief but detailed information like what your site is about, what features you offer, and anything else thats useful to your demographic.
Next is advertise your forum/business. Since its directed at other guilds, WoW is a pretty massive place to advertise this to, and you should take advantage of it. Create level 1 alt characters on other servers, and just start contacting guild members/masters to and let them know about your site. Don't spam them in game, just get them to come and check it out.
Great point, and I'd agree. Not once place do I actually see a description of what your forum does (to topic creator) except the title in the blue bar at the top of the browser. There isn't really a mention of Guild/clan hosting, and it all seems so... generic. There are no topical forums, no real support forums. It all seems just like any other computer site with all the same forums that brings in. The icons are good, but they have nothing to do with the topic. I mean, look at most of it. All but one forum are nothing to do with the subject at hand, or what your site actually offers. It looks professional, but needs to look as such while STILL keeping to the theme. Nothing wrong with you as an individual, or anything like that, just that the reason it might not be catching on so much isn't about promotion and such like, but because it looks like... any other forum about technology.
You also need to make the banner stand out a bit more, since it's not much bigger than ordinary text. Plus, you have a hosting site... with ONE mention of hosting on the page. The other tips are pretty much the same. Fill up all the forums, give the impression of activity, promote it well and add features that your members might like and that may further your site.
Edit: Oh, and don't be too disheartened... you can't expect big activity in a month or less...