Check this out:
MAKE YOUR OWN SUBLIMINAL CD'S AND MP3'S IN MINUTES!
http://www.subliminalrecorder.com/
If Apple is using this, it would explain why so people like iTunes.
:-P
This reminds me of the Saved by the Bell episode when Zach put a subliminal message in a tape that he let Kelly borrow, who found out and then played a joke on him by giving it to Belding who played it over the whole school's intercom. The result was that everyone (including Slater) wanted Zach to go to the dance with him/her.
It's a somewhat silly idea, but still we all love Saved by the Bell. But, I do think there is something to be learned here. If you start messing with planting ideas in people's minds using techniques like this, you're asking for trouble.