Why do people keep buying CDs?
Because my car only has a CD player; and because I can afford to.
I have enough disposable income that it's just less faff to buy a CD. With any other method, I have to find blank CDs, fire up my dusty old computer that still has a CD burner, work out which illegal source of music hasn't been shut down this month, work out which illegal filesharing client software isn't pumped full of adware. Then I discover the ink in my CD-labelling pen has dried up, or the blank CDs themselves go wrong.
Yes, I could probably buy some MP3-playing gadget that I could wire into the car's CD player, although DIY isn't my forte. I suppose I could pay somebody at a garage to fit one. Or, much simpler, I could just keep buying CDs.
Then again, I'm talking about the kind of CDs you find near the tills in petrol stations. I don't think my purchases of Eddie Stobart's Keep On Truckin' are keeping the charts alive.