Services you have never heard of that have around 100mm users or more
WeChat www.wechatapp.com –> from the makers of QQ, Tencent
Nimbuzz www.nimbuzz.com –> IM aggregator
Mig33 –> Indonesia centric
Whatsapp is probably at 100mm
Services like Viber, Path, Kik are in the 10-20mm range I think. Bigger ones like Line, Kakao are at 50mm+.
LinkedIn has 150mm users. Twitter 250? Facebook 1bn. Google+ has like 250mm they say.
Those numbers don’t seem so impressive anymore.