Fair enough; but you're still going to limit your liability. Assume your customer spends $10K/month with you; or $120K/year. Would you ever commit to compensating them $1MM+ in the event of an outage? Of course not. It would be business suicide.
If you want that level of uptime, you build out your own place (i.e. Amazon, Facebook, Google). If you're not big enough to build your own, you live with the possibility of downtime.