Change product position in block based on number of terms (weighted)

I think it would be great if when you relate products by the taxonomy terms it ordered them by how many terms that related product shares with the current one. So for example you are looking at a movie with terms such as, theme - drama, director - Martin Scorsese, actor - Robert DeNiro the first related movies would also have those 3 terms, theme - drama, director - Martin Scorsese, actor - Robert DeNiro, followed by movies with only two terms, and so on.