The chart below shows what happened to CDs in the music industry. After a dramatic drop in sales from 2000 to 2015, the industry is now growing again with the rise of subscription music.
As an investor, the chart is a reminder of the importance of the question “what is this business’ role in the world?”. If you fooled yourself into believing that you were a seller of music CDs rather than music, you could have believed that you defined the industry.
MR=MC 