14. The method for dynamically selecting attributes indicative of human users, evaluating users and selectively presenting offers to estimated human users as recited in claim 10 , the method further comprising: receiving data pertaining to a purchase by a purchaser of a ticket; and estimating whether the purchaser possessed the user characteristic, wherein the initial set of attributes is modified based on the estimation.
15. The method for dynamically selecting attributes indicative of human users, evaluating users and selectively presenting offers to estimated human users as recited in claim 14 , the method further comprising: biasing ticket offerings to favor users in the first group over users in the second group, wherein the purchasing data indicated whether a user in the first group attended an event.