The list of "similar users" in one's profile is a good idea, but I would change some implementation details. In particular, it should discredit people from being "similar" if they do not have many favorites at all. Most of the people who are "similar" to me have in the range of one to five favorites, of which I might have favorited two. While that makes us pretty similar by percentage, it doesn't actually help me find other people whose favorites I should pay attention to. I would say you can't appear in other people's 'similar' listings unless you have at least ... 10? 20? favorites.
Updated by 7HS