Very few cloud SLA's seem to have teeth to me. Amazon's SLA gives service credit equal to 10% of your total bill for the billing period if they blow past the 0.05%. This is a lot better than some cloud providers that will simply prorate the downtime, but pretty crappy in terms of actual business compensation. It's equivalent to a sales discount almost any organization with a sales staff could write without thinking about it - meaning Amazon is still making money on every customer even when they've blown past their SLA - assuming every single customer fills out the forms to apply for the discount. Hint: Many won't, see mail in rebates.

A number of tier 1 network providers offer certain customers SLA's that are clearly in place to prove that they invest in redundancy and disaster planning. ex: less than 99.99% --> 10% credit. less than 99.90% --> no charges for the circuit in the billing period.

This reflects an understanding that downtime can hurt your business/infrastructure far in excess of the measurable percentage.