Marketing is all, Microsoft tried a irc client in 1998 but failed then...msn! Msn started lacking features from the old top IM (ICQ). Off-line messages is recent in Msn and in ICQ its default.
Marketing can surpass any feature.
Here in Brazil a popular network died in 2007 then few days ago I received a spam from another network (rival?) talking about new features like hostserv with colors (yeah colors in your host @_@), number of users is increasing now, but serious because of those spams small networks will never become big
