Great feedback, thanks. I just made some revisions to try and make the narrative arc clearer. To clarify here as well: - CF techniques are definitely superior

Great feedback, thanks. I just made some revisions to try and make the narrative arc clearer. To clarify here as well: - CF techniques are definitely superior for answering the question "what else might this user want to buy?" in a generic way, when you have preference/purchase data for that user. - Content-based techniques are great for making recommendations in a context where what you really want is something more akin to automatic curation, and you may not have the necessary preference information about a visitor to apply CF (e.g. an anonymous user viewing a product details page, vs. a logged in user who has previously bought products). A content-based approach can solve the cold-start problem for CF. You're right that I could have done a much better job in the original post -- I've since added information to the effect of the above. Thanks very much for the comment!