Duncan C. nominates this Wall Street Journal chart. A sure sign of trouble is when the accompanying article waxes about a new on-line music service, another one that practises "loss-based" pricing, i.e. priced to ensure a loss; the article does not mention anything about this chart. It just stood on the side, like wallpaper.
Its key message does not seem to connect with the data. "Growth in digital music downloads has not been rapid enough to offset declining CD sales": but in terms of total units, the chart shows a small dropoff in CD sales coupled with an explosion in digital songs sold. Besides, the units of discs, songs and iPods are not directly comparable.
Source: "Listen to Music Free But Pay to Carry", Wall Street Journal, June 5, 2007.