Here's a nice quote from a blog entry entitled Apple iTunes Store Environmental Impact. ... I had no idea. How many CDs and DVDs do you have? How many have you thrown away?
Sooner or later, all Music CD’s and the Jewel Cases they are packaged in will end up in a landfill somewhere. CD’s are mostly manufactured from Aluminum and Polycarbonate along with Lacquer, Dyes, and other materials such as water, glass, and nickel. Most of these materials must also be processed before manufacturers can use them to make CD’s. As an example, to make plastic, crude oil from the ground is combined with natural gas and chemicals in a processing plant. In addition to manufacturing, there are transportation costs (shipping CD’s in trucks to the store) as well as packaging costs (the jewel cases, shrink wrap, etc.) to consider as well.
By buying your music from the Apple Store, you are helping to prevent a stack of CD’s 2.6 miles high from having to be manufactured PER DAY.