How do I configure Rdio to scrobble to Last.fm?
Connect your Last.fm and Rdio accounts and scrobble what you listen to by visiting your Account Settings page. Hover over your name in the upper-righthand corner and select Settings.
Click External to manage your connections with Facebook, Twitter and Last.fm. You may also visit this link directly.
Click Connect next to the Last.fm logo to begin.
If you’re not already logged into Last.fm, enter your Last.fm login information. If you are already logged in, select “Yes, allow access.” You should then see “You have connected your Last FM account.” in your external settings on Rdio.
To remove your connection with Last.fm, view the External tab in Settings and click Remove next to the Last.fm logo.