Do you have a service guarantee?
Some companies in the industry provide guaranteed services. Similar to FedEx guaranteed overnight delivery; fulfillment companies can guarantee accuracy of the order or shipment time. Keep in mind that does not mean they ship all orders correctly. It means they hold themselves accountable for their mistakes.
The best companies in the industry provide a 100% accuracy packaging guarantee and a 100% shipment guarantee within one business day or the order is free.
They also provide additional guaranteed services, such as inventory accuracy. This is a good way to compare companies because if they are not prepared to offer you a money back guarantee this could indicate questionable reliability.