16. The method according to claim 11 , wherein: the travel service selection criteria includes affective and emotive data identified by the buyer and relative weights identified by the buyer for said data; the receiving from the buyer input changing the service selection criteria includes receiving from the buyer input changing the weights assigned to the service selection criteria; and the showing to the buyer the effect of changing said service selection criteria includes showing to the buyer the effect on the plurality of the service response sets of changing said weights assigned to the service selection criteria.
17. The method according to claim 16 , wherein, for each of the services and service enhancers, the travel provider modifies values of one or more of said attributes, including a unit price, capacity, bundling parameters, and recommendation schemes.