Remove SPOF
It's always annoyed me that most DNS providers do not allow zone transfers thus it is not possible to say sign up with a number of dns providers, have your master server with one (or indeed on your own server) and then configure each suppliers servers as slaves which only accept/request updates from the master.
If this was allowed it would seem you could limit the effect of dns issues as hopefully at least some of your providers would be online.
Having a single supplier for dns has always struck me as flawed regardless of the claims from those suppliers of how fantastic their infrastructure is.
Biting the hand that feeds IT
