After managing in a company where five nines (99.999% uptime) was a big selling point, it's somewhat amusing to see MySpace crowing over their industry-leading reliability of 99.96%, or what we'd call 'three and a half nines'. That's over 210 minutes of downtime each year.

Poor Twitter is angling for over 7,000 annual minutes of downtime with their 98.72% uptime.

I'm not making light of their technology and scale challenges, but these levels of uptime would never be acceptable in an enterprise environment.