The office friend

Do you know what an office friend is? Are you being one?
It's not a friend that you have in the work space but someone you would only keep in touch when you are in the office, through the internet. You probably live in different cities and you know each other for quite a while, which tries to justify the term "friend' used here at the first place.
Anyway. An office friend, since geographically disconnected, it's not so possible to hang out with during your own time. But an office friend, you wouldn't try to reach him/her during weekend or days off, which is either because you got a life so you don't think of getting online writing mails or following fb or chatting on skype, or, you got a boy friend or a girl friend that makes it a little inappropriate to get online writing mails or following fb or chatting on skype. Some like that.

Here the office friend.
Are you being one? To how many people?

I'm an office friend to some ones and that makes me think the friendship out there is dubious.
It's not cynical, is it?