And they're shifting 500k downloads a week of featured tracks.
iPhone developer Tapulous has now sold more than five million songs through the in-game music store for its Tap Tap Revenge games.
What's more, every week the store's featured track - which is made available for free - is racking up more than 500,000 downloads from players.
The news comes as Tapulous announces a licensing deal with major label Warner Music Group to make four new premium games based on its artists in the next year.
The companies aren't saying which artists, just that the games will include a mixture of hits, remixes, live tracks and rarities.
However, Tapulous will also launch a dedicated WMG channel in its Tap Tap Revenge store, selling tracks from the label's catalogue.
"With Tapulous' exciting family of games, we're adding yet another compelling content experience and offering our artists a unique and powerful platform for engaging with fans around the world," says Mark Pinkus, SVP of worldwide licensing at Rhino Entertainment, which handles WMG's catalogue activities.
Tapulous says it now has 30 million users, with its games installed by more than 30% of iPhone and iPod touch users. That huge community will help it to promote the WMG premium games as they are released in the next 12 months.