Ars Technica: “The click-to-buy links aren’t necessarily limited to music videos, either. Google has begun inserting purchase links for things like video games too, exemplified by the link to buy Spore from Amazon underneath a trailer for Spore. And, as we hinted in the beginning of this article, Google says that it would like to be able to offer this kind of thing for other YouTube videos with soundtracks—presumably the kind that users put together. It would be kind of cool to watch somebody’s mashup on YouTube with a link to buy the song (or songs?) that were used as part of the soundtrack in the video.
In order to do that, however, Google would have to scan the audio fingerprint of each video and try to identify the song in question. Luckily for YouTube, the company is already using audio fingerprinting technology for its music label partners in order to help filter out unauthorized uploads. Perhaps this is one of the non-evil ways ways the company plans to use such technology—it benefits both the viewer and the content owner, instead of just the content owner.”