I don't see why not. It may not be your everyday typical relationship between two people who can see each other physically on a daily basis but as stated, advances in technology today are making it so there is plenty of alternatives to that which may not be as good but at least they are there.
I don't think it would be easy depending how serious and strong the feelings of the people involved are but if you are aware of the fact that it'll be hard and are willing to deal with that, then why not? You never know what the future holds also and you could end up meeting eventually and taking it further from there and it becoming something more then an online relationship.












It's a no-brainer really 



Quite alot of meet ups are done locally, both as friends and relationships. Teenage ones may progress when you approach university, you might even meet someone you talked to online at a university you are going to - afterall, if you're "friends" or interested with this person, you're sure to mention where you're heading off to for your university placements and if they're thinking about university, they may mention what they're up to as well. It's not black and white - you'll either fail or die, or not get anywhere, there are loads of different instances when discussing online relationships 