Several record labels such as Sony Music and Universal Music have been courting with the idea brought about by a Seattle based company called Activated Content which places audio Watermarks on MP3 files. The purpose of these watermarks range from digital tracking of content, to marketing matrix that allow companies to get statistics on who has listened to their particular audio.
Earlier, Universal Music had declared that it was going to offer music without content protecting DRM on it. Universal is listed on Activated Content's website as a known partner. The CEO of Activated Content refused to comment on whether or not these DRM-free music offerings were going to have audio watermarks placed on them or not.
Additionally, although Activated Content has their own watermarking technology, it was announced that they have signed an agreement with Microsoft's research division, who is currently in charge of the development of DRM techniques and standards.
Source:
PCWorld







