I'd actually tend to think that the people who took the time out to seek the geek dating service are probably less likely to be scary than the people on one of the bigger dating services.
I'd be more concerned about your friend though. If he thinks there are no interesting women around, I have to question what he's looking for? I'm a woman and everywhere I've ever lived/worked/gone to school there have been a lot of "interesting" women who were into sci-fi, fantasy, etc.
If he's looking for a supermodel looking woman who also has every single same interest as him, chances are he's not going to find her, because "perfect" people do not exist, and everyone has at least SOME degree of flaw. I'm not saying your friend is doing this, but I've seen it happen time and time again, where someone is seeking perfection that simply is unrealistic. I'm not saying anyone should have lesser "standards" for themselves, but of the people I know who have used dating services, all of their "perfect matches" have turned out to be not so perfect after all.
*sigh*
I always kind of question these things when I hear both men and women say they don't know anyone interesting. IMO, they just aren't asking people the right questions to get to know them. Or they have unrealistic expectations of physical attractiveness.
If your friend is honestly just looking for someone with similiar interests as him, I'd be really shocked if he can't find someone. I guess, if he can't , then this is the way to go, but just tell him to be really careful. I think guys tend to think women are the only ones vulnerable to online/ dating service crazy people, but I've seen my guy friends end up with some really scary, unstable women.
Sorry to be so skeptical, but I've just seen too many people get burned by women & men they've met through dating services. Myself, I'm more of a wait and see who walks into my life person. That's how I met my boyfriend. I think these things work out best when you don't try to force them. *shrugs*
I know there are millions out there who disagree.