That brings up an interesting edge case, of proxy buyers. Someone in the US wants something that’s only sold in, say, Japan (ex., P-Bandai model kits), and uses a proxy buyer service to have someone in Japan buy it and send it to them in the US. There are a couple ways the logistics can be handled, but in at least some the proxy takes ownership of the goods before re-shipping them. Functionally similar to the “fulfilled by Amazon” items. How this ruling affects liability in that case could be interesting, though it may be niche enough to not truly concern anyone.

Thus third party products largely look like they are sold by Amazon, so liability might make sense. This likely also applies to retailers who also sell third party products online such as Walmart.

Strict online marketplaces such as eBay and Etsy may not be affected depending on the breadth of any ruling. These marketplaces do not sell products directly, all sales on the website are by third party sellers. Yet eBay started out only providing a marketplace. Payment, shipping, returns, etc. were between the buyer and seller (with the only quality control the user’s feedback score). Today eBay handles most (all?) payments, largely requires shipping be done through the site, and enforces other requirements on sellers. So in one sense they are responding to customer demand for a more regulated market and in another sense have provided the groundwork for a lawsuit arguing they are responsible for the quality of products sold on the site.