In most bars it seems like you can't swing a dead cat without hitting some asshole willing to lie to a woman to get her into bed. The only difference on the Internet is that it's easier to lie about appearance and age... but once you've met the guy you know whether he was honest(ish) about those things. If he's the kind of guy to lie about other personal details (job, hobbies, criminal history, etc), it doesn't make a difference whether you met him on the street or online.

Quite a while back I used to date online quite a bit, but after a few duds I abandoned the medium. A few months later, I got a reply to my latent online profile, from a girl who seemed like a spiffy number, so we went out on a date, which led to some more dates... long story short, we celebrated our first wedding anniversary last month.

So for me, it worked out well. For my wife, it was a disaster. :D