[randallsquared]

Easy problems can become nearly impossible at scale.

[jmathai]

I'll take GMail with 99% uptime over running Horde in my basement with 100% uptime.

[Groxx]

You get 100% uptime from your ISP? Dang. Where can I sign up?

[packetslave]

Yep. If something has a "one in a million" chance of occurring, you'll run into it 17 times per hour (based on Comscore's Sept 2013 estimates of Google search volume)