After several months of beta testing, an ad-supported Web site that allows visitors to download music and videos free of charge is set to launch today in the U.S. and Canada.

The SpiralFrog music service hopes to attract downloaders away from pirate download sites by offering virus and trojan free music files. Although billed as free, the downloads have a cost and that is the downloader’s time. Before users can download the files, they must view various advertisements and must periodically log-in to the SpiralFrog site.

All the songs available for download will have some form of Digital Rights management (DRM) which will require owners to log on to the Spiral Frog website at least once a month. If users don't log-in, the songs will be locked up and downloaders will be unable to play them.

Provided users sign into the service on a regular basis, they will be able to copy songs to two portable media players.

SpiralFrog says it will be offering more than 800,000 songs and 3,500 music videos for download and expects to have more than 2 million tracks over the next several months.

I predict this will NOT be popular. Nothing makes me click "close" faster than having to watch pre-rolls at news or video sites like CNN or CTV. I assume the pre-rolls will be even longer before you can download a single 128mbps (if that is what it will be) MP3 or WMA. Plus what happens if you change your PC? Will the monthly login fail to activate your music library thinking it has been copied to a another PC? Does anyone know?