NewKt ji, In my personal opinion, the most important things to make any sort of relationships strong, are honesty and trust. If you trust your online friend and you are honest to him/her, then online friendship is possible. After all, you need not to know how s/he looks like to be his/her friend, isn't it?
 And i totally agree Destiny 2007, sometimes you could find really good people.
Anyways, thanks a lot for your comments.