Napster, which pioneered the concept of free music shared via the web, has moved back to that model -- with a catch.
Napster's basic service is now entirely advertising-subsidized, allowing users to stream music from the company's library of about 2 million songs, for free.
The catch, however, is that each song may be played only five times, after which the user is asked to subscribe to Napster's paid service, which costs $9.95 per month, or $14.95 per month