Online chatting is good when it makes some sense i.e. when we chat with some one to know something for better.
By chatting online you can get some information, advise, or just topics on entertainment like discussing movies,etc.
Online chatting with an unknown person without any aim, would be just a time pass and the time spent will be useless.
Mostly, online chatting will prove economical since it is free . i.e. chatting online is preferred over chatting on phone/mobiles in terms of bill payment.
Mostly, these days I find the students go online chatting hours together and enjoy the chat too! God alone knows, why they don't get tired of online chatting.
With best wishes
Myth is the greatest human weaknes.