Site Usage

Is this site meant only for women, or can men join too? I got an email asking to invite more folks. This is a good site, very useful info and good convos too. I wondered though, should I invite only women or is it acceptable to invite men too? I am not trying to be political, or step on anyone's toes, just asking a legit question. And I know the whole "legally we cannot discriminate" stuff, but realistically, are men "socially permitted" I guess is the better way to phrase the question?