I seem to have a different experience. Everyone migrated to Yahoo or AIM with MSN a distant third. In my social circle, yahoo was the king of chat for a very long time.
Parent might be in Europe and you in the US. Back in those days that's how the IM market shares were roughly distributed among my peers.
Yep. I'm in Brazil and the friends I mentioned are in Europe.
We moved to Skype because of the end-to-end encryption, the group chats feature, the ability to talk and the network effect from others using it and us not wanting to use two clients at once. Oh, and with Skype file transfers would just work, while no ICQ client would ever let me initiate a file transfer to another person, or if it did, it would go though servers on the other end of the world.