This very interesting article came up in my inbox this afternoon. It talks about the different approaches to Instant Messaging(IM) by ICQ and AIM and how Jabber tries to cover both options. I must admit that I have been unaware of the Offline Message features but could use them for the more complex communications—or would an email be better for that purpose anyway? It does archive so I am not sure I agree with Julian.
Part of the point of my article is that there are at least three different perceived message types—email, short messages, and chat messages. There are a lot of things that I’d be willing to send to a person in a chat message or a short message that I’m not willing to bother sending an email for. This is why I think offline messaging is important—if it’s something you definitely want archived you’ll send an email no matter what, but if it’s just a quick little link to something transient, it’s more likely to go in an IM message.
The technical differences between an offline IM and an email aren’t nearly as important as the UI differences. Technically, there should be little difference, yes. But technically, people who used to send offline messages should still do so when they use iChat—but they don’t.