I discover vk because I was search some books online to my students...I like Vk but I have allready  twitter and facebook...

thank you Don was a nice explication now is more clear

Wechat is totally different with Skype. Wechat is a mobile phone App, while Skype is a all-platform software that is widely used all over the world.

Wechat is like WhatsApp.

Also Wechat is under censorship of Chinese goverment.

I learned about WeChat from you :) I think in any country likes and used any sites - for example in Russia, Ukraine, Belarus etc. so popular Vkontakte ( https://vk.com/) -it is social network like Facebook. But in USA, England, and any western country more people used Facebook... It's normal :) sorry for my English, Good luck !

because skype looks more professional is what some people use in work when can't travelling to another country...you can do calls with werbcame if you wish and sharing fills and multi-conversations...is the 1st time I hear about Wechat probably in Europe just few persons know about it...is like youtube the chinises use youku