As others have mentioned, this was likely added automatically by Quartz to get a few extra cents/dollars from any story linking to an Amazon product/page.

Quartz probably has a page somewhere disclaiming their affiliate linking policy (which is likely: "we have affiliate links. They are separate and do not change the content of a story.") You can see an example of Wired's policy here: https://www.wired.com/2015/11/affiliate-link-policy/