Er... No idea.
I mean, I sort of fell into a 'relationship' of sorts online through a chat service, but that was strictly an online thing.
The closest we ever got was exchanging a picture or two.
I don't even think we ever got around to mentioning our real names to one another.
Still... Something about it was unfortunately real enough...
It wouldn't have ended so badly if it hadn't ended up involving real feelings.
So, I can imagine under different circumstances, if the people involved had a bit more courage, and a bit more willingness to cross that line from the virtual world to the real one, I can certainly see how the situation I ended up in could, in principle have led to an actual relationship.
I doubt it happens often, but knowing what I experienced, I'm guessing it's reasonably possible.
But I would say it's the kind of thing that just... Happens.
If you go looking for it, you'll never find it.
What happened to me never crossed that line into the real world, but I would say it got pretty intense that notwithstanding.
However, regardless of that, neither of us set out with that as an intent.
Hell, it took me ages, and many weird encounters to even realise, that, in fact, if you were to translate what we had been doing virtually into the real world, we would have been dating for quite a while...
So even that realisation can pass you by if you're not paying attention.
But, to begin with, you need a basic level of chemistry with a person.
Then... You need to be willing to meet them in the real world...
And, finally, that chemistry needs to survive this transition.
Believe me, that is by no means guaranteed.
I mean, it's all well and good to say you fell in love with someone's personality, and not their looks. (which you probably did, if it started online), but that doesn't mean the attraction you have for someone when all you've got is avatars, some online text/voice chats, and at best a few photos, can really survive unscathed with you meeting this person, and experiencing them 'in the flesh' as it were at close proximity...
It's a nice ideal, but it rarely is that simple...
Still, that's pretty much how it goes. Give or take a couple of steps...