[shaddi]

To be fair, they're not explicitly charging twice as much for consistent reads. You get consistent reads until you exceed your provisioned read amount, which unfortunately is measured in these odd units of "read capacity"). It's not clear (to me, anyway) if the 2x number represents something accurate about resource usage or if it's just a provisioning guideline.

That said, what provisioned capacity means in DynamoDB is pretty opaque. Great point about the utility of latency information for developers.

[pbailis]

For a fixed amount of throughput, if I want consistent reads, I pay x dollars. If I'm okay with eventual consistency, I can pay x/2 dollars and get the same throughput.

Conflating resource usage, pricing, and consistency using a single metric (here, price) seems confusing, especially without the right metrics to guide devs.