SirClicksalot writes to tell us that EMI is launching the first ad-supported peer-to-peer music downloading service called Qtrax. With Qtrax users will have two tiers of membership available to them, which EMI hopes will draw in a large segment of users to try it out and graduate many of them to stay on with a monthly fee or purchase music permanently. From the article "In the ad-supported, free tier, users will be able to search the network for specific tracks, and those tracks registered with Qtrax will be made available for download in Qtrax's proprietary ".mpq" file format. Users will then be able to play the downloaded .mpq file in full-fidelity sound quality for a pre-defined number of times. Each time a consumer plays a track, the Qtrax player will also offer fans click-to-buy purchase options, as well as the opportunity to upgrade to a premium subscription service for a flat monthly fee."