[bigiain]

FWIW, I have many many companies as customers for whom I've offered pricing for three, four, and five nines of reliability (for mobile app backends, not residential ISP service, but lets run with it any way).

Not a single one of them has ever signed up for anything more expensive than three nines. Only a few have even discussed the differences between 3 and 4 nines solutions.

I'm reasonably sure I'd choose the same for my home internet connection - if offered representative pricing based on costs of providing 3, 4, or 5 nines, or possibly even 2 nines - I'd choose the least expensive because losing a few minutes or even occasionally 15mins a day of connectivity at home (or maybe more realistically an ~8 hour outage per month) really isn't going to bug me greatly - not if it's two or more orders of magnitude cheaper than a four of five nines connection.