16. The method of claim 15 , wherein defining the hierarchical structure of pricing models comprises setting a root pricing model for the set of billable items within the telephony communications platform system and setting a set of pricing sub-models that sparsely over-ride at least a portion of the root pricing model for a subset of the billable items in the telephony communication platform system.
16. The method of claim 15 , wherein defining the hierarchical structure of pricing models comprises setting a root pricing model for the set of billable items within the telephony communications platform system and setting a set of pricing sub-models that sparsely over-ride at least a portion of the root pricing model for a subset of the billable items in the telephony communication platform system. 17. The method of claim 16 , wherein the pricing models are mutable through an administrators interface, and wherein setting a set of pricing sub-models comprises setting a first sub-model over-rides a parent sub-model for set of billable items.