Agreed. I think highly contextualized recommendations are the most helpful. As another example, I frequently find the "often purchased together" section to be

Agreed. I think highly contextualized recommendations are the most helpful. As another example, I frequently find the "often purchased together" section to be very helpful. That might be the only recommendation system that I've ever used more than once. I would say that's an example of recommendations working. However, in my personal experience, I rarely find "general" recommendations helpful.