AI Infects the IPod

A company has developed an app/plugin for the IPod that analyzes the songs you skip to avoid the songs you don't want to hear (thus, playing the songs you do want to hear) at the moment.
From the article:

Instead of a random shuffle, our ’smart shuffle’ uses some cool machine learning to analyze what music you want to hear based on the songs you skip and the ones you don’t. Within just a few skips, we can play the songs that fit your current mood and activity. Whether you’re working out, walking in the park or road-tripping with your friends, our new Instinctiv Shuffle will be able to understand what you want to hear within just a few skips

I have seen it work, and the most interesting part is that it doesn't bog down the IPod, yet doesn't require any song preprocessing either. So it must be analyzing song attributes and building its database in the background.
hmm, I wonder how it works...