He's right. I did it. But, why does the author think Macs are more profitable? The market is smaller. As it's smaller, it's less differentiated providing fe

He's right. I did it. But, why does the author think Macs are more profitable? The market is smaller. As it's smaller, it's less differentiated providing fewer niche markets. I'm not saying the author is wrong, but I would like to know the author's thinking.