Oh sure, if you’re using something like that I can get behind it. But then you’re back to the network effect. Probably slightly mitigated since everybody has email, even if they’re not getting it in a pretty IM format and won’t be replying to it on the spot.
Not sure what to say to that. Nobody in my group would consider classic email and IMs equivalent, unless you’re layering an extra UI layer on top like what the other commentor mentioned.