Last.fm is releasing figures today based on its relaunch as an ad-supported streaming service. It looks like the three free full plays of music tracks are driving users to build more playlists and tags, which of course will again pull in more full tracks, and so on. The CBS-owned music discovery network said that in the UK the site saw a 32% increase in listeners, 30% increase in page-views with a 19% increase in unique visitors. In the US its unique listeners increased 85% on the day of launch (Jan. 23) versus the previous Wednesday (Jan. 16). That means the key metric of ‘engagement’ is up. The site also had a 45% increase in page views and 27% increase in unique visitors in the U.S. during the same time period.