Jessica Simpson's unprotected MP3 track on sale now.

Yahoo Music's recent offering of a personalized Jessica Simpson song is being hailed as under-the-table test of how unprotected MP3 files may sell online.

The Simpson track, "A Public Affair," allows buyers to select a customized "shout out" that will insert the buyer's name into the song lyrics, sung by the blond bombshell. Noted in the offer is that the track is formatted to work with any MP3 player, including the iPod.

No other tracks on Yahoo Music are compatible with the iPod because Apple Computer only allows two types of files to work with its device—those formatted in its proprietary FariPlay technology bought from the iTunes Music Store, and unprotected MP3 files which contain no digital rights management technology.

The Simpson track carries a price tag of $1.99, decidedly more than the standard 99 cents that Yahoo, iTunes and other services offer. The company says the higher price tag is due to the personalization option, not because it's more valuable as a track without DRM.

However Yahoo recently began sending Yahoo Music subscribers an e-mail survey that among other questions asked whether they would pay more for a track without DRM that contained no limitations, listing the proposed price as $1.09. In addition, Yahoo Music chief David Goldberg has in the past publicly stated his preference for selling music without DRM.