MSN Messenger's market share is 61%
It is MSN Messenger that boasts the largest share of instant messaging software, IM in short. The proportion is 61%. It is hard to imagine that the results of this survey are European and American, so it is difficult to think that it applies to Japan unconditionally, but it seems that it is still big that you are in a state where you can use it as soon as you enter Windows.
M-Dollar: 60% of IM users prefer MSN Messenger
By the way Skype's market share is 14%. Only 3% of them are US users. That is, Skype's overseas usage rate is higher in EU countries. Is there a result like this because there are many people in the EU area who make international calls crossing borders?