[Staydecent]

I really like the idea of using email for, well, everything. And I prefer blogging by email (like posterous) and implemented it myself for App Engine (https://gist.github.com/462907).

As for this generic crud service. I think the problem is, just as you don't know how it could be useful, neither do others. A hosted db would be useful through an API, but communicating with email programmatically is probably a larger overhead compared to a standard GET or POST request.

[Skywing]

I can't put my finger on it, but for some reason I just can't stop brainstorming about this concept. I think it'd need to be marketed as a lower level service than Posterous. It wouldn't create a nice web page for you, it would just store the data and let you do whatever you want with it.

I guess you're right though. If somebody was going to code something and use a database, they'd probably just go with something a little more direct.

Edit: Also, in regards to overhead of GET versus an SMTP message. I think the payload for SMTP might be about the same or maybe even less than GET in size.