Saturated but most players are unprofitable. Amazon has an infinite well of money to not only out-price the competition but sustain a loss for long enough that

Saturated but most players are unprofitable. Amazon has an infinite well of money to not only out-price the competition but sustain a loss for long enough that the competition might actually die. Amazon also makes revenue off of attached services to merchants (Fulfillment by Amazon, the webstore, etc). This is part of the reason why Square has been trying to buy up merchant value-add companies.