Eminem’s former production team, F.B.T. Productions, sued Universal over the issue in 2007. The brothers behind F.B.T. claimed that, when Universal provided music to stores like iTunes, it was actually “licensing” the tunes to another distributor rather than distributing them itself.
The distinction makes a huge difference in the royalty rate: Eminem received a 12 percent royalty on CDs, which Universal distributed, but a 50 percent royalty whenever the music was “licensed.”
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Eminem producers lose bid for massive iTunes royalties – Ars Technica