Last.fm, the CBS Corporation-owned social networking music Web site, released figures today that showed it to be the fastest growing online music network in the U.S., as their free-on-demand music service saw a unique listener increase of 92% since it was launched four weeks ago. In addition, since the launch of free-on-demand, unique visitors continued to show sustained growth, up 59%, while page views increased 58%. Last.fm receives more than 21 million active users worldwide every month. (PR)