The advantage to online dating is that you "meet" a lot more chicks. Meeting more people increases your chances. It's the shotgun approach to dating.
I am married, so this is an academic discussion for me.
Please note that it's just a personal observation, not meant to apply to anyone else. I'm an engineer who knows from experience that it's one thing to converse in writing, when you have time to check your writing and reasoning; and quite another to do it face to face, with no breathing room.
I'm fine, if there's nothing Serious lurking in the background. If you add "Serious" to the mix (and "looking to get married" would qualify), it would take a lot of face-to-face time for me to be comfortable.