Also, you can use more robust models (like signing) to detect tampering; this is a markup approach for blended text; whether you trust the sender or not is another matter.
Agree. I think one way retail banks could reinvent themselves is as a trusted escrow and analytics platform for your money across all other tools: Venmo, Paypal, etc. They already do this for Visa (which they don't own, but work with.)
Yeah, it's overkill because the book is about this stuff. Normally this much analysis is narcissism. We even left some stuff out (like the Facebook page traffic and ramp-up.)
Agree completely about getting the button wording right. We'll try some different buttons; the 37Signals example (where they changed from "buy" to "see plans and pricing" and doubled conversions) shows this is something to spend a lot of time on. Candidly, we had only a few days to get things live, so they're still rough around the edges.
Our publishers are O'Reilly, so they're delightfully open (encouraging, even) about sharing all kinds of content. And there's simply too much for the book to hold. Great point that we should make some content just for list subscribers.
We're in the middle of interviews with a bunch of big tech companies about the metrics they watched in the early days, and we should probably put some of that aside just for subscribers.