Comment by bjornsing

> Good point. Could have put a bit more work into that.

On second thought, and after looking at my cost estimates, the reason DynamoDB ends up costing about the same as S3 for this kind of use case is storage costs. DynamoDB is a lot cheaper than S3 to write to, but 5-10x more expensive to keep data stored in. So after about 16-32 months you reach break even.