I've been running the Last-FM/iScrobbler plugin for quite some time (since August 5th, 2004), and although I frequently let the computer (unnamed) run unencumbered, I do point my playlists in certain directions, via randomizations, playlists, or my favorite selection tool, Doug Adams' applescript BlockParty. (Apparently, I wrote about BlockParty previously, per a google search. In my defense, that was over a year ago).
So, strange how certain trends percolate up the slipstream, and also strange how certain data is manipulated by methodology. A perfectly reasonable expectation is that over several months, certain artists will be played more frequently because their catalog is deeper. Dylan, Neil Young,
6 month artist stats
vs.
12 month artist list stats
6 month album stats
vs.
12 month album stats
And after all that jibber-jabber-wine-fuzzy typing, the impulse to even look at my Last-fm stats was because I noticed that I have rated every song of Dylan's John Wesley Harding album as 4 star or higher. In my iTunes universe, I try to give star ratings to every track, eventually, as many playlists are built using star rating as a data point.