Comment by onion2k

You can't have 100% uptime. It's unfeasible, especially for a startup. You should be telling your customers that downtime might happen, sometimes for reasons beyond your control, and that if it does then you'll do your best to recover and to compensate them for the inconvenience. You should cultivate a relationship with your early customers that makes them feel bad for you when there's an outage rather than angry about how it impacts them. Maybe even go as far as firing the customers who give you a hard time over it. That way if your cloud provider falls over it's really annoying but not a big deal.

Your cloud provider blocking your business from running is far worse.