"Big businesses can be big in different ways. They can be big absolutely, like Wal-Mart— with billions of dollars in sales annually, making it the biggest business in the nation— without selling more than a modest percentage of the total merchandise in its industry as a whole. Other businesses can be big in the sense of making a high percentage of all the sales in its industry, as Microsoft does with sales of operating systems for personal computers around the world. There are major economic differences between bigness in these two senses. An absolute monopoly in one industry may be smaller in size than a much larger company in another industry where there are numerous competitors."