Earlier quoted context omitted.
This button isn't about saving time, it's about preventing the instances of not having something when you need it. The moment when you realize you need more of something is typically when you're using it. If you can literally just hit a button to order more, that's a significant change from having to do something else to order more.
> This button isn't about saving time ... it's about creating a barrier to exit so that your customers won't comparison shop for different brands of detergent.
Its about the API and what new purchasing flows will be created by eager startups, resulting in new MRR for Amazon.