How does iTunes make its decision as to what artwork to provide? I'm trying to download Album Art by right-clicking a track in iTunes and choosing Get Album Artwork.  Sometimes this works fine, but sometimes iTunes finds the wrong Album.  

As an example, I have A Taste Of Things To Come from the Mortal Kombat Soundtrack.:



But this is the only track on that same album with Album Art, so I ask iTunes to Get Album Art for the second track.  This is what it finds:



The Quigley soundtrack, starring Gary Busey and Oz Perkins.  

How does iTunes make its decision as to what artwork to provide for any given track?  And ideally, how can I encourage iTunes to make better choices?

I'm running iTunes 10.6.0.40 on a Windows 7 PC.
iTunes uses an external site to search for album art.  I don't remember exactly which site it is, but I do remember that it was crowdsourced, so there's a high likelihood that, especially with relatively rare music, it will get the wrong thing.