I thought most businesses financed payroll with periodic short-term loans? If you can be 100% sure you'll get the credit it's better to put that money to work than have it lying around.
(Then one day the credit dries up and you're hosed, I'm not commenting on the wisdom of the strategy but my understanding was it is standard practice.)
If you have regular income and outgoings, and large efficiencies to scale that could make sense, mostly done through factoring, ie credit against invoices, so secured lending. It is less sensible in businesses with more variable cash flows and nothing much to secure borrowing against.
(Then one day the credit dries up and you're hosed, I'm not commenting on the wisdom of the strategy but my understanding was it is standard practice.)