OTOH, I've learned to treat IMs as emails to a degree: often I'll send a message to someone who's online and expect that they'll likely see it. This might be a

OTOH, I've learned to treat IMs as emails to a degree: often I'll send a message to someone who's online and expect that they'll likely see it. This might be a quirk of the clients we use, but it's very email-like. The difference is less one of speed and more one of an ephemeral inbox. (In how it's treated by typical use cases; obviously, IM logging makes it less ephemeral.)