Ah, female pirates! Anne Bonney, Mary Reade, er, probably some others.
I checked the Sword of the New World web site, and of the 38 screenshots they have there 11 show only female avatars, 17 show mixed male/female, 7 show distance (crowd) shots and 3 show only male avatars. One showed an avatar I couldn't tell the gender of for sure, but I think it's probably male.
Female characters feature so much in the ads for virtual worlds that a casual observer might think they were played ovewhelmingly by women. Of course, the fact that the women invariably look hot is the giveaway that they're mainly aimed at men, but still, that doesn't seem to have unduly hurt Second Life, which does very well for female players:
[Aside: notice how her arm cuts through her wing. This was on Second Life's front page; is lack of collision detection accepted as the norm nowadays?]
So if you want to attract players, male or female, you should always use hot female avatars for promotional purposes?
Not if your target is ...
teenage boys.