Best selling single on Amazon UK 

Amazon have released sales charts for various sections and for the mp3 section, Killing in the Name of, is the best selling single, here is a source http://uk.movies.yahoo.com/mamma-miabeats-harry-potter-to-amazon%E2%80%99s-bestselling-dvd-ever-154132631.html
I'm going be bold and just add it to the article.