[discodave]

The three are: Prime, Marketplace (3rd party), AWS.

> After two decades of risk taking and teamwork, and with generous helpings of good fortune all along the way, we are now happily wed to what I believe are three such life partners: Marketplace, Prime, and AWS. Each of these offerings was a bold bet at first, and sensible people worried (often!) that they could not work. But at this point, it’s become pretty clear how special they are and how lucky we are to have them.

> With good execution and a bit of continuing good luck, Marketplace, Prime, and AWS can be serving customers and earning financial returns for many years to come.

From the Amazon 2014 letter to shareholders: https://s2.q4cdn.com/299287126/files/doc_financials/annual/A...

It's kinda interesting that Devices (Alexa/Kindle) and 1st party retail are not called out as flywheels. Advertising and Alexa are other candidates for the next flywheel I believe. I think the reason they're not there yet is that they're not self-sustaining, i.e. like Logistics, they're growing but their growth is driven by the other flywheels.