iTunes Top-Seller charts only reflect the last 24 hr period.
All labels are getting the same, non-negotiable deal from Apple: which wants three-year reseller agreements to buy material wholesale, with nonexclusive, worldwide distribution rights.
Apple apparently wants to deal with invited labels only - no individual artists.
Suppliers may not sell albums on iTunes without also selling each track as a single, and the album price must be the same or less than the sum of their tracks.
6-7m copies of iTunes are in use.
More than 75% of songs have sold at least once.
45% of all songs have been bought as part of an album.
Exclusive tracks are the best sellers.