20. The non-transitory computer-readable medium of claim 19 , wherein the method further comprises, for each of the first media content item and the second media content item, identifying the plurality of media content items as recommended media content items based on the single rank-ordered list.
20. The non-transitory computer-readable medium of claim 19 , wherein the method further comprises, for each of the first media content item and the second media content item, identifying the plurality of media content items as recommended media content items based on the single rank-ordered list. 21. The non-transitory computer-readable medium of claim 20 , wherein the single rank-ordered list of the second plurality of topics generated for the first media content item and the second media content item is generated by: (a) determining topics associated with the first media content item and the second media content item; (b) for each of the topics, obtaining a rank-ordered list of second topics generated for the topic as the first topic; and (c) combining all of the rank-ordered lists obtained at (b) together using the distance information as ranking score to form the single rank-ordered list.