Can iTunes Genius (or song metadata) be improved so songs without a match can use the feature? My question boils down to: "Technically, how does the Genius feature work?" so that I may use it in instances where it fails to fine enough matches for a specific song.

Part of this question is &mdash; what is stored in your library or meta-data on iTunes or on your iPhone that allows the songs to combine into auto-playlists? In other words, what is it delivering when it says "Delivering your Genius results..."

More than just academically interesting, I'm wondering if there is anything I can do to adjust the metadata of those songs that get the Genius error messages so that they work.  I have had a few lately that are popular songs and should have been able to find results easily but didn't.
The way I understand it, Genius not only uses your mp3's metatags to organize Genius information, but also gets a lot of information from what people put in their playlists. This makes sense, as the point of Genius is to automatically put together a list of song that go together, without having to do it manually.

I read an article about this once, where a guy had Genius create a playlist for him, and he couldn't figure out for the life of him what the songs had in common. They were from all different years, genres, etc., even including spoken word. Finally, he realized that the tracks all had one thing in common -- they were Canadian. Of course, this isn't the most intelligent behaviour as tracks that are Canadian are not necessarily those you would like to listen to in succession. But of course, it would not be uncommon for people to create a "Canadian" playlist for other reasons than listening to it as a collection, and that's why Genius thought they might go together. The Genius feature slowly loses its charm as the track progresses from Celine Dion to a CBC Radio archive to (heaven forbid) Justin Bieber.