1. A computer-implemented method of providing a brand sponsorship environment, the method comprising: a. providing a computer-implemented platform establishing a sponsorship junction involving a first set of trigger-monitorable activities defined by a set of audience providers, the platform implementing processes including: for each audience provider of the set of audience providers: serving over a network, by a server, the server coupled to a storage system and coupled to the network, data defining a screen on a client computer of an audience provider representative by which the audience provider representative can specify at least a specified subset of the first set of trigger-monitorable activities, the specified subset being monitored by corresponding triggers; and receiving over the network and storing by the server data, from the client computer of such audience provider representative, defining the specified subset of trigger-monitorable activities; for each sponsoring brand of the set of sponsoring brands: serving over the network, by the server, data defining a screen on a client computer of a sponsoring brand representative by which the sponsoring brand representative can specify a reward that can be offered to a participating end user; and receiving over the network and storing by the server data from the client computer of such sponsoring brand representative defining the reward; wherein at least one of all of the trigger-monitorable activities in the specified subset utilizes a Physical Trigger; b. storing, by the server, for each given sponsoring brand, a sponsor selection that establishes a set of linkages, each linkage defining a correspondence between at least one member of the specified subset of trigger-monitorable activities and the reward applicable to the given sponsoring brand, so as to define sponsorship by the given sponsoring brand of the at least one activity of an audience provider in the set of audience providers; and c. receiving, by the server, over a period of time, a set of trigger messages, applicable to the participating end-user, and, responsive to the stored sponsor selection of such brand's set of linkages, associating, by the server, the set of trigger messages with the account of a pertinent one of the set of audience providers and relaying the set of trigger messages to the corresponding set of sponsoring brands.