Aurora I/O optimized config saved 90% DB cost(graphite.dev)

  S3 would be a tiered monthly subscription service based on average storage use, with a free tier. Customers would choose a monthly subscription rate based on how much data they typically needed to store. Simple ... The engineering team was ready to move on to the next question.

  Except that day we never got to the next question. We kept discussing this question. We really did not know how developers would use S3 when it launched. Would they store mostly large objects with low retrieval rates? Small objects with high retrieval rates? How often would updates happen versus reads? ... All those factors were unknown yet could meaningfully impact our costs ... was there a way to structure our pricing [to] ensure that it would be affordable to our customers and to Amazon?

  ... the discussion moved away from a tiered subscription pricing strategy and toward a cost-following strategy. "Cost following" means that your pricing model is driven primarily by your costs, which are then passed on to your customer. This is what construction companies use, because building your customer's gazebo out of redwood will cost you a lot more than building it out of pine.

  If we were to use a cost-following strategy, we'd be sacrificing the simplicity of subscription pricing, but both our customers and Amazon would benefit. With cost following, whatever the developer did with S3, they would use it in a way that would meet their requirements, and they would strive to minimise their cost and, therefore, our cost too. There would be no gaming of the system, and we wouldn't have to estimate how the mythical average customer would use S3 to set our prices.