Everyone will experience downtime at some point, but the question is whether this is a chronic problem and fundamental shortcoming or if it is an extraordinary, unusual event?
Here's a report going back to April of 2007 (4.25 years) on the three sites listed above in the same order:
Knocking on wood over here, we are very proud of this record. It's the result of our investment in infrastructure, people and services. Although this uptime isn't recognized like a new feature or updated design, it is every bit as important and we want to say thanks to the people who keep us running shiny side up.