Comment by leo_mck

I see all kind of theories about the misterious nature of facebook recommendations. I believe that they use all kind of complex things but most of those unexpected recommendations could be explained by assuming that facebook recommend you people that have being cheking you out. If you saw someone on the street and that person check your facebook, they are recommended to you and it looks like magic because you did nothing. I do not know if this is the case but it is simple and seems to explain a lot of those strange recommendations.