YouTube has added a no-brainer: affiliate download links from Amazon (NSDQ: AMZN) and iTunes for music and other kinds of downloads, from any specific video on its site. For instance, if a user is viewing a video of music artist, then links from Amazon and iTunes will appear on the page for song download. The Google-owned company is touting this as a larger e-commerce platform play, and will add music, movies, TV shows, concert tickets and other products down the line. For now on the music side this has only been enabled for EMI and Universal Music artists...hard to see why others would resist. Also this only works in U.S. as YouTube content partners who are using its content ID system (for managing and anti-piracy) can also enable these links on user-generated content.