6. The system of claim 2 , wherein the computer-executable instructions further cause the one or more hardware processor devices to: maintain a group profile for the group of users, the group profile describing media selections made by the group of users over a span of time, each entry in the group profile including: an identity of a prior media item that has been selected; and context information pertaining to a circumstance in which the prior media item has been selected.
6. The system of claim 2 , wherein the computer-executable instructions further cause the one or more hardware processor devices to: maintain a group profile for the group of users, the group profile describing media selections made by the group of users over a span of time, each entry in the group profile including: an identity of a prior media item that has been selected; and context information pertaining to a circumstance in which the prior media item has been selected. 7. The system of claim 6 , wherein the computer-executable instructions further cause the one or more hardware processor devices to: automatically select a new media item based at least on the group profile, without any user in the group of users explicitly specifying the new media item in a new message.