While often ignored, item-to-item similarity recommenders work really well for new items and have been the basis for Amazon's and YouTube's early recommendation algorithms
https://glinden.blogspot.com/2011/02/youtube-uses-amazons-re...
https://glinden.blogspot.com/2011/02/youtube-uses-amazons-re...
My point was around the utility of marketing, at least in theory. If I release a new brand of baked beans, how would a recommender based on past sales (and combinations of sales) know to recommend it to anyone. Marketing allows it to go up the list (unfairly, according to the post I was replying to).