I think the ad-tech industry has tapped into what can only be called -- and no offense to anyone here -- "virtue signalling." There's no doubt studies done on this, hence the new "controversial" sort of nature of some of the advertising. Who knew that Gillette and Nike were so interested in social issues, and not a bottom line PNL result. In the same way, perhaps, Amazon marketing teams found some research to suggest that same "heart-string tugging" mechanism can be combined as a "sweetener" to get you to do things you otherwise wouldn't do -- like subscribe to "buy this too" notifications.