99% 99.9% - What Does That Mean?

Alex Castellanos: I think we all have a good idea of what numbers like 99% 99.9% mean, but you translate that into a certain number of minutes or hours per month. He says people want to be four nines reliable, which means 99.99% right? And that translates to to mere minutes. "It's a great way to translate things so that people really understand that when they're asking for 99.999% ... it doesn't make sense," he says.