Is it wise to make friends on line?

I think it is wise to make friends on online.
First,it is fun,you can know so many friends from different places.You can broaden your knowledge about others' culture and convention which you may not find in books.
secondly,when talking to friends online,you don't have to care about your appearance (except you use webcam) or manners,you feel much more comfortable than talking in the reality.
Thirdly,It saves you money.If you invite your friends to your home or meet them in the cafe,you will spend money anyway.Online chatting must be cheaper!
Last but not the least,you can improve your English if you make friends with people in English-speaking countries,you have more chances to practice English in listening,speaking,reading and writing.