Microsoft has stated that the recently announced interop between Yahoo! Messenger and Windows Live Messenger has created the world's largest IM network. Exactly how big is it compared to the others? Check out the table below which contains ComScore numbers from May 2006. The excerpt is from the Silicon Valley Sleuth blog post entitled Google Talk fails to find an audience

Google's instant messaging service ranks at the bottom of the overall ranking, which is dominated by MSN Messenger/Windows Live Messenger (204m subscribers), Yahoo! Messenger (78m), AIM (34m) and ICQ (33.9m).

ICQ actually grew by more than 10 per cent year-over-year, the data indicated. The network is owned by AOL and is considered the first mainstream instant messaging application.

Another interesting factoid from the data is that E-buddy (formerly known as E-messenger) rules the unified messenger category ahead of Trillian, claiming 3.9m vs. 1.3m unique visitors.

E-buddy offers on online unified messenger for MSN, AOL and Yahoo – no installation required. The great benefit is that it allows users on bolted down corporate networks to connect to instant messaging services without any intervention from the IT department.

Interestingly enough, when I read geek blogs I tend to see people assume that Trillian, Meebo and AOL Instant Messenger are the dominant applications in their category. People often state anecdotally that "All my friends are using it so it must be #1", given that IM buddy lists are really social networks it's unsurprising when everyone you know uses the same IM application in much the same way that is unsurprising that everyone you know hangs out at the same bar or coffee shop. However one doesn't extrapolate the popularity of a bar or coffee shop just because everyone you know likes it. The same applies to online hangouts whether they be instant messaging applications, social networking sites, or even photo sharing sites.