100 were part of full-album downloads, 7 albums total.
2 of those were replacements for albums I owned years ago on cassette.
4 were soundtracks.
1 was a total whim. (Idinia Menzel, "I Stand," totally worth it.)
Of the other 53:
34 I first heard on the traditional radio, most of which predate iTunes by a decade or more.
3 I found on Internet radio stations.
3 I discovered in the POA.
5 I had to buy after someone made an awesome fanvid on YouTube.
2 I first heard on the radio at work.
2 are from TV shows, for which they were written specifically.
3 are preexisting songs that I first heard in a TV show.
1 is from a commercial. Yes, the Liberty Mutual one.