Beats Music launches next week, but there is already frenetic activity among its established rivals, particularly those seeing free streams as the best way to compete with Beats’ subscription-only offering. Rdio is the latest with an announcement, revealing yesterday that it is making its full, on-demand web service free. And making money by… “As part of this update, we’ve added in-stream messaging to Rdio on the web. These new ads are short and sweet. Free listeners will hear a mix of new feature announcements, messages from partner brands, notifications about exclusive content, and other helpful tips,” explained Rdio in a blog post. So Rdio’s offering now involves ad-supported free streams online, a free personal-radio service within its mobile apps, and then the $9.99-a-month premium tier to remove ads on the web and get the full functionality on mobile. It’s feature-matching with Spotify, as both aim to make their free funnels as wide as possible to convert more users to premium down the line.