1. A method for generating shipping rules configured to make shipping decisions on behalf of a user, said method comprising: compiling, by a processor-based system of a shipping services operator, raw shipping data based on shipments made by a plurality of shippers, wherein, for each of the shipments made by the plurality of shippers, the raw shipping data comprises at least one of shipment weight information, address information, shipment size information, shipping container type information, and item type information; compiling, by the processor-based system, user defined data comprising information associated with at least one of one or more customer categories, one or more pricing categories, one or more delivery time categories, and one or more quality of service levels provided to said processor-based system by said user; deriving information associated with one or more shipments to generate derived data, the derived data comprising at least one of calculated shipping rates, delivery dates, and delivery times; automatically constructing, by said processor-based system for said user, a plurality of shipping processing rules for making shipping decisions, wherein the plurality of shipping processing rules are constructed based on rule parameters and a data set, wherein the rule parameters comprise conditions and operators, the conditions comprising shipping attribute information for making shipping processing decisions, determinations, or both, the operators comprising at least one of logical operators and mathematical operators that are applied to said conditions to make said shipping processing decisions, determinations, or both, determinations, or both, wherein the data set comprises the raw shipping data, the user defined data, and the derived data, and wherein constructing, by said processor-based system, the plurality of shipping processing rules comprises constructing at least one shipping processing rule configured to select, based on an amount of time that a customer has been using a service offered by said user, a type of shipping service for shipment of an item purchased from said user by said customer; analyzing, by said processor-based system, the plurality of shipping processing rules to select shipping processing rules that define a set of shipping processing rules for generating postage indicia for said user, wherein said set of shipping processing rules includes said at least one shipping processing rule constructed based, at least in part, on said amount of time that said customer has been using said service, wherein said analyzing comprises: analyzing, by said processor-based system, said plurality of shipping processing rules to identify whether a conflict exists between at least two shipping processing rules, wherein a conflict is identified based on a determination that applying the same conditions to said at least two shipping processing rules presents different shipping decisions; and automatically resolving, by said processor-based system, said conflict between said at least two shipping processing rules based on a conflict resolution parameter that specifies an outcome criterion, wherein automatically resolving the conflict comprises: identifying, by said processor-based system, a particular shipping processing rule of the at least two shipping processing rules that satisfies the outcome criterion, wherein, when the outcome criterion is a time-based outcome criterion, the particular shipping processing rule of the at least two shipping processing rules that satisfies the outcome criterion corresponds to a shipping processing rule that provides a most rapid delivery time, wherein, when the outcome criterion is a cost-based outcome criterion, the particular shipping processing rule of the at least two shipping processing rules that satisfies the outcome criterion corresponds to a shipping processing rule that provides a lowest shipping cost, wherein, when the outcome criterion is a level of service-based outcome criterion, the particular shipping processing rule of the at least two shipping processing rules that satisfies the outcome criterion corresponds to a shipping processing rule that provides a highest level of service; and selecting, by said processor-based system, the particular shipping processing rule that satisfies the outcome criterion for inclusion in the set of shipping processing rules; and generating a postage indicium for an item to be shipped, wherein said generating comprises: receiving shipping information for said item to be shipped, and utilizing said set of shipping processing rules and said shipping information to generate said postage indicium for said item to be shipped.