and whats more,
online friends often let you see their inner personality, their soul, their heart, which is prob more important than how they look like.
You can meet them from the depth of them as they dare to say things which they would never, out there in reality.
And so, i myslef think that my online friends (eventho we have seen eachother and we hang in real too) know me the best, like real me, my opinions, my humor,even my honesty. they also remember more things and facts about me... they have my personality deeply analyzed.
simply said; online friends know your soul more, whereas offline friends focus on how you look like and so.
in the end i agree with all people above; friend is friend. Both kinds are same real. But in my opinion its easier to meet through online, easier to open up to them, easier to share personal information, and they keep it better as they read it, read it as many times as they want... whereas in real, you rather focus on how they look like, what they drink, what they wear, you have more living memories with them but less deep in that personal point.
Not saying my opinion is the right one, but i met my closest friends online, then we hung for a long, collected informations, facts, got to know eachother ... and then we met in a person. In this moment we already knew everything about eachother so the real contact went smooth. These ones know me best as a complex person.