1. A computer-implemented method for booking one or more advertisements to an impression using a targeting dimension dictionary, the method comprising: constructing, in memory, the targeting dimension dictionary using a targeting dimension dictionary schema, the targeting dimension dictionary schema comprising at least one of, a targeting dimension object, a dimension attribute type object, an application attribute type object; and retrieving, in a computer, the targeting dimension dictionary for booking the one or more advertisements to the impression using a target predicate wherein the target predicate is constructed at least in part using the targeting dimension dictionary.