Yeah, supporting both uses would be critical. I think you're right that making sure it could interop with existing email clients in as painless a way as possible would be critical.
I'm not sure how much of a chance it would have of succeeding (I'd like it, but would anyone else?). One thing that gives me a bit of hope is the rising popularity recently of email newsletters on specific topics or from specific writers/thought-leaders.
>I'm not sure how much of a chance it would have of succeeding (I'd like it, but would anyone else?)
It may, because it doesn't have to build it's own network effect, it can piggyback on emails existing userbase, which is basically everyone.
I was talking with my housemate, we came up with the idea of a combination push and pull following mechanism. I can offer you the option to follow me by sending you a mail with the X-SOCIAL header and a "follow offer" header content, plus a really simple mail body that says "hey, substance just asked you to join their social updates list. it seems you don't have a social client, <click here> to get one". If you've got a social client installed already, the body gets hidden and you get the follow offer in your social client.
However, you could also send me a mail with the X-SOCIAL "follow request" header, and a similar introductory body: "Hey, skewart wants to keep in touch with you via social mail. Download a social client <here> to connect with them". If I have a social client installed, I get a friend request instead.
The great thing is, your email inbox has a timestamped record of all these requests, so it's like a somewhat unreliable replayable social history, which means if I don't have a social client, I can read the introductory body, go grab a social client and come back, and it will re-parse my inbox and offer me the same follow request, no need for you to resend it.
I'm going to start talking to a few people that might have good input and have a swing at writing a comprehensive draft specification, as best I can. Might not be a bad idea to have a proof-of-concept/reference implementation being developed alongside. Wanna take this to a different medium? Skype, wickr, steam, email?
I'm not sure how much of a chance it would have of succeeding (I'd like it, but would anyone else?). One thing that gives me a bit of hope is the rising popularity recently of email newsletters on specific topics or from specific writers/thought-leaders.