10. A recommendation selection system, comprising: a rule evaluator for producing a set of candidate recommendations; and a recommendation selector that uses a probabilistic purchase decision model to rank each of the candidate recommendations using one or more purchase decision gating factors to calculate, for each candidate recommendation, a boost in expected margin resulting from the candidate recommendation being issued, as compared to the candidate recommendation not being issued.
10. A recommendation selection system, comprising: a rule evaluator for producing a set of candidate recommendations; and a recommendation selector that uses a probabilistic purchase decision model to rank each of the candidate recommendations using one or more purchase decision gating factors to calculate, for each candidate recommendation, a boost in expected margin resulting from the candidate recommendation being issued, as compared to the candidate recommendation not being issued. 13. The system of claim 10 , wherein the probabilistic purchase decision model is implemented as a Bayesian network.