I don't mean to hammer this comment page with this point, but just to clarify this since the product is so new: It really has very little to do with writes per second. High volume writes are Dynamo's bread and butter.

His cost issues come from the large item size.

No, I have very small items. The cost issues come from the large number of items.

I thought I read 33kb somewhere in there. If so, by dynamodb standards, that's not a small item. If I mis-attributed that 33kb number, then I kindly retract what I said :D

I have 33kB blocks which are stored on S3 (after aggregating them into objects of up to 8 MB). I have key-value pairs which are 24 bytes and 53 bytes long.