What would you recommend for persistent disk storage on AWS instead of EBS then? Assuming you need to put database files somewhere where they don't disappear when instances terminate, and your database can access them.
They cluster their databases across multiple instances, availability zones and regions, and back them up constantly to S3. Their ultimate recovery plan is to restore from backup if necessary, which is pretty much the same as assuming EBS will corrupt your data.
While it's far from trivial to do it that way, they seem to be the most successful user of the AWS systems.
The only exception I've seen are people with very spiky traffic patterns, who can save a bit of money by only running instances when they need them - but even then I suspect that the money saved might be less than you'd think.
Amazon wins for APIs and convenience but not for price.