1. In an electronic system for distributing promotional offers, a method of targeting a plurality of customers from a customer database for distribution of limited quantities of promotional offers, the method comprising: generating a plurality of scores for said plurality of customers, each said score being associated with one said customer and with one said offer, and each said score measuring a probability that the associated customer will make a purchase in accordance with the associated offer; identifying, by a computing device in said electronic system, a highest score in said plurality of scores; determining: a customer, from said plurality of customers, associated with said highest score, and a first promotional offer, from said plurality of promotional offers, associated with said highest score; assigning said first promotional offer to a first personalized offer list for said customer if said first promotional offer satisfies one or more constraints on one or more of the following: a total number of first promotional offers that are distributable, and a total number of promotional offers that are distributable to said customer; successively repeating said identifying, determining and assigning steps for each next highest score until all of the promotional offers in said plurality of promotional offers have been assigned to personalized offer lists; and distributing one or more of the promotional offers to one or more of the customers in said plurality of customers.