Start a business where no one will give you terms and you have to pay COD on everything. Then score a contract with a university who orders $50,000-$75,000 a month. When you're a struggling new business, no one will give you terms.
I can't count the number of times the UPS guy had to call someone to get the cash. The biggest single truck load of CODs was $34,000. The Driver, who I knew pretty well, was shaking. It was approximately his take-home for the year. He never left the lot until the boss and two others showed up. After a while, 10,000-15,000 became routine once or twice a week. Interest expense eventually made the whole thing not worthwhile but it was interesting for a while. Your customers will only accept net-30 and your suppliers want COD, eating a month of interest on 10s of thousands sucks.
what were you selling to a university that would have brought you that kind of money? Office supplies and bulk foodstuffs would be the only things that I could think would be in that high of a demand.