A trivial example: I got an XM Satellite Radio, which is an impressive market response to the poverty of broadcast radio. One of the channels I like the best is
The Joint, which plays reggae. Beyond Bob Marley, Peter Tosh, Burning Spear and a few others, I don't know enough about reggae to know what I like and don't like. Through XM I am learning. (For example, I don't much care for Johnny Nash's Guava Jam, which The Joint plays far too often.)
One of the things I heard on The Joint was Buju Banton's version of the 23rd Psalm. Based on that, I bought his CD
Unchained Spirit.
So the marketplace led me to listen to the 23rd Psalm as a regular part of my day. Pretty neat.