• Amazon is a big company, but what does that mean? How big is ‘big’? What does ‘dominant’ or ‘scale’ or ‘huge’ mean when US retail is $6 trillion a year?
• Running the numbers, Amazon has about 35% of US ecommerce. But, it competes with physical retailers as well – it competes with Macy’s, Walmart and Barnes & Noble. On that basis, Amazon’s real market share of its real target market is closer to 6% (it’s 2/3 the size of Walmart)
• Regulators pick and choose market definitions depending on their objective, and this will probably happen to Amazon – it’s definitely dominant in books and definitely not in cars. But if we’re going to worry about the scale of the Amazon machine, which scale are we talking about? That’s a political question as much as it’s an economic one.

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