1. A method performed at an order fulfillment server of an online merchants to third party warehouse providers broker and order fulfillment system, comprising receiving, on a common merchant interface of the order fulfillment server, inbound shipment orders from online merchants, each inbound shipment order identifying one or more goods to be stored in one or more of a plurality of third party warehouses, wherein at least some of the plurality of third party warehouses are owned and operated by different third party warehouse providers and are not owned or operated by any of the online merchants; for each inbound shipment order, performing the following, communicating a representation of that inbound shipment order on a common warehouse interface with a set of one or more of the plurality of third party warehouses that will store the goods, wherein the common warehouse interface allows each of the third party warehouse providers to communicate with the order fulfillment server in a common way, and receiving a set of one or more inbound shipment order parameters regarding that inbound shipment order on the common warehouse interface from the set of third party warehouses that received that inbound shipment order, wherein the set inbound shipment order parameters includes whether the one or more goods corresponding with each inbound shipment order has been received, wherein the common warehouse interface allows each of the different third party warehouse providers to view only their respective one or more outstanding inbound shipment orders and input the set of inbound shipment order parameters for each of their one or more outstanding inbound shipment orders; receiving outbound shipping orders from, or on behalf of, the online merchants, each outbound shipping order identifying one or more types of goods, a quantity of those one or more types of goods, and a shipping address; for each outbound shipping order, performing the following: selecting which one or more of the plurality of third party warehouses to fulfill the outbound shipping order from one or more of the inbound shipments, communicating a representation of that outbound shipping order on the common warehouse interface to the selected one or more of the plurality of third party warehouses, and receiving on the common warehouse interface, a set of one or more outbound shipping order parameters for that outbound shipping order from the selected third party warehouse warehouses, wherein the set of outbound shipping order parameters includes whether the outstanding shipping order is complete, wherein the common warehouse interface allows each of the different third party warehouse providers to view only their respective one or more outstanding outbound shipping orders and input the set of outbound shipping order parameters for each of their one or more outstanding outbound shipping orders; for each one of the plurality of third party warehouses and a given time period, the order fulfillment server generating a reverse invoice, wherein said generating the reverse invoice includes, aggregating one or more services completed by that third party warehouse over the given time period based on at least the received inbound shipment order parameters and the received outbound shipping order parameters, determining an amount of money owed to a third party warehouse provider corresponding with that third party warehouse for the aggregated one or more services completed, aggregating one or more service problems attributed to that third party warehouse over the given time period, including services not completed on time and services completed erroneously based on at least the received inbound shipment order parameters and the received outbound shipping order parameters, determining an amount of money to charge the third party warehouse provider for the aggregated one or more service problems, and reducing the amount of money owed to the third party warehouse provider for the one or more services completed by the amount of money to charge the third party warehouse provider for the one or more service problems; and responsive to determining that one of the plurality of third party warehouses is experiencing a failure, the order fulfillment server automatically generating one or more disaster plans to compensate for outstanding outbound shipping orders that are affected by the failure, said automatically generating including, determining one or more outstanding outbound shipping orders affected by the failure; and for each of those one or more outstanding outbound shipping orders, performing the following: determining an alternate one or more of the plurality of third party warehouses to fulfill the one or more outstanding outbound shipping orders based on a set of one or more factors, and communicating a representation of the outstanding outbound shipping order to the alternate one or more of the plurality of third party warehouses.