I'm sorry, G,
but that article is very misleading. Music labels make no effort, at all, to sell physical copies of singles. They are a promo tool that "lose" money on each sale. There are relatively few available for sale, and now, with the proliferation of $.99 singles on internet sites, they are vastly outnumbered by the number available via itunes, Napster, et. al.
Statistics don't lie. Statisticians do.