Email is a great way to communicate
Here is what I have realized: email really does the trick
(check out the Hacker News discussion for the Monkey Mace article)
I've seen a trend recently in startups to create a new form of communication with an emphasis on effectiveness. The vast majority of implementations fail to address the key requisite of communication platforms: critical mass.
If a service has an email bridge, I am far more likely to use that service. A perfect example of this is the GitHub Issues email bridge, which allows users to reply to issues directly from their mail client.
I'm certainly not arguing that email is the pinnacle of human communication standards. Email isn't perfect. It has a lot of cruft from being so old. It has disgusting errors when messages fail to deliver. It allows for forgery of senders, and cryptographically signing messages is extremely uncommon.
But it works. It's something that everyone uses, and I don't have to send anybody an invitation to a service whose utility is questionable and whose longevity is even more so.