“

This online ad customization technique is known as behavioral targeting, but Pandora adds a music layer. Pandora has collected song preference and other details about more than 200 million registered users, and those people have expressed their song likes and dislikes by pressing the site’s thumbs-up and thumbs-down buttons more than 35 billion times. Because Pandora needs to understand the type of device a listener is using in order to deliver songs in a playable format, its system also knows whether people are tuning in from their cars, from iPhones or Android phones or from desktops.

So it seems only logical for the company to start seeking correlations between users’ listening habits and the kinds of ads they might be most receptive to.

”

– http://www.nytimes.com/2014/01/05/technology/pandora-mines-users-data-to-better-target-ads.html?ref=todayspaper