[marcod]

I can see this both ways. Obviously, nobody is forced to sell to Costco, Amazon, or Walmart, but in a business with thin margins, like Retail, the only way to stay afloat is to sell high numbers. A quasi-monopoly does force vendors to comply in a way.

[danielmarkbruce]

Costco meets no reasonable person's definition of monopoly. Not quasi, not sort of, not anything. They do a couple hundred bill of sales in a multi-trillion dollar market. Sub 10% share.