If you don't, it you can remain signed in from multiple locations.
The fact that AIM doesn't automatically log you out from a previous session when you begin a new one on another device means that you can keep multiple devicessay a PC and a phonelogged on at the same time.
The only service aside from AIM and ICQ that the client interacts with is Facebook chat, which is a big one.
But you still can't use the AIM client to chat with MSN or Yahoo buddies directly.
You can also go through a wizard-and-invitation scheme to import buddies from other accounts like Yahoo!
Mail and Hotmail, but they'll have to have or create AIM accounts.
You can easily add buddies from AIM and ICQ and start chatting with them immediately.
Multiple Log-Ons I like that AIM 7.3 can log out of all your other devices that are running instances of the service.
Just type "1" into the chat field to the AOL System Message contact when it contacts you to let you know you're signed in from multiple locations.
You do, however, see more buddy info and a bigger profile picture when you roll the mouse over an entry.
For comparison, Windows Live Messenger shows a list of options when you roll the mouse cursor over an entry, such as Send IM, Send a video message, and View social updates.