Great read. I feel bad for the Is.gd people. They might've had the most unfortunately timed outage from an extremely rare ISP issue that will never happen again and will forever be labeled as the service that's "not 100% available". Just pretty darn close.
They were marked as 99.99% available, that's nothing to feel bad about. "Both Bit.ly and Goo.gl delivered perfect availability, and Is.gd came awfully close."