Seattle - Social music discovery service iLike announced on Tuesday that it has surpassed one million registered users. The service includes an iTunes plug-in that monitors what users are listening to and provides personalized recommendations, as well as alerts on local concerts. The company said it is now processing over 200 million monthly track plays by its users. Seattle-based iLike also operates the indie music community GarageBand.com and personal broadcasting service Gcast.com.