[barrkel]

In fact, a little known feature of Costco's business model is their ability to sell all their stock well before their suppliers require payment for goods (Net 30)? This means they have an effectively _negative_ cash conversion cycle, or in other words, their suppliers are paying to stock their products.

AFAIK most supermarkets run this model; when I was in school in Ireland in the 90s, this model was explained to me with reference to the main Irish chains. They end up with a big chunk of free cash that they invest.