SpiralFrog, the free ad-supported web-based music service, has launched a site in North America touting its offering as a "viable alternative to piracy".

The company said that its research had shown that music enthusiasts have traditionally gone to one site for discovery and another for downloading.

"Music fans demand fast access to high quality audio and video files and they want their music free, but they would still like the music owners to be paid for their work and creativity," said Joe Mohen, chairman and founder of SpiralFrog.

"Our answer to this seemingly impossible equation is to allow our audience to download songs and video at no cost and to compensate music owners by sharing the advertising revenue."

SpiralFrog will allow anyone to access and download files from a library of more than 800,000 songs and 3,500 music videos, with new content being added every day.

The site will feature extensive search capabilities allowing users to search by artist and genre, and users will also see relevant targeted advertising which SpiralFrog claims will not interfere with their enjoyment of the music.

"SpiralFrog will integrate advertising in a compelling way so that we enrich the overall user experience while becoming a must-have channel for advertisers, " said George Hayes, senior vice president of marketing and sales at SpiralFrog.

"The more we can make the advertising relevant to users' tastes and demands through tailor-made programmes and micro-targeting, the more potential we create for a meaningful experience."

SpiralFrog believes that its model provides an alternative to piracy and illicit file-sharing.

Despite efforts by the music industry, and the wide availability of digital music providers, online media measurement firm BigChampagne estimates that only one in 40 downloads is paid for.

In contrast to file-sharing services, SpiralFrog offers free and legal music in a "safe environment, with consistent quality and download time".

The company claims that users are never at risk of downloading viruses, and never have to worry about adware or spyware.

"By sharing advertising revenues with artists, labels, publishers and performing rights organisations, SpiralFrog monetises free music consumption," the company said.