Social Media is certainly an option for recruiting. We could make a Twitter/Facebook page for the clan, which I think would be more effective(and convenient) than using our personal pages.
The most effective method in my opinion, would be to establish ourselves in a few communities dedicated to Smash (like AiB, as n10 suggested). We would basically be preaching to the choir. lol
There's also no reason why we couldn't do both.
Before all of this recruiting though, we have a lot internal organization to do. Events, responsibilites, ect.
I think our course of action will become clearer as the release date approaches. :p