1. A computer-implemented method comprising: receiving a criteria-encoded message, wherein the criteria-encoded message is generated from a behavior-criteria vector that indicates criteria for selecting a recipient of a digital coupon; generating, by a computing device, a user-behavior vector to indicate one or more behavior patterns of an end-user; encoding the user-behavior vector to produce a behavior-encoded message; determining whether the end-user is eligible to receive the digital coupon based on the criteria-encoded message and the behavior-encoded message; and if so, presenting the digital coupon to the end-user.