If you consider Payment Risk from an exporter's perspective, nothing raises blood pressure more than to hear a prospective buyer abroad ask for Open Account payment terms. We don't get comfortable until we move down the risk spectrum, moving away from Open Account, through Documents Against Acceptance, Documents Against Payment, toward the perceived more secure methods of payment such as Confirmed Letters of Credit. And, there was a time we could ask for and expect to receive Cash in Advance.
If you place yourself in your buyer's shoes, however, you will note that the inverse of the above is true: your buyer doesn't get comfortable until he/she moves away from Cash in Advance, L/Cs, etc., and moves toward Open Account. The challenge is how to be responsive to your clients' financing needs without being hung out to dry in the process.
One way is through the use of Credit Risk Insurance to protect open account sales.