questioner

Q: What pricing models does Amazon use for selling web services?

Amazon uses several pricing models for selling web services:

* Free usage: Several of our services are available for no charge, or have free usage tiers, which allow you to use the service at no charge until you reach a specific usage level.
* Pay-for-usage pricing: In this model, you are charged on the first of each month only for your actual usage of the web service during the previous month. For example, if you make 8,000 requests to a web service that costs $0.001 per request in the month of January, you will be charged $8.00 for that web service on February 1st. If you make no requests in January, you won't be charged for that web service on February 1st.
* Subscription pricing: When you sign up for a web service with subscription pricing, you will be billed at the beginning of the month for access to the web service during that month. Depending on the web service, your subscription fee may grant you an unlimited number of requests or your usage may be capped at a certain amount of usage. Specific details about pricing for each web service are available on the AWS web site.