Media hub devices with passive monitoring of user devices and targeted media transmission through in-channel transmission or shifted channel transmission

A system for passively monitoring user devices, the system comprising:

• a media hub device comprising one or more physical processors programmed by one or more computer program instructions to:
• passively monitor, at a point of sale terminal, one or more user devices on a wireless communication channel;
• obtain identification information for the one or more user devices, the identification information including at least first identification information for a first user device;
• identify a location data for the one or more user devices based on a received signal strength via a triangulation and strength of one or more radio-frequency signals in the wireless communication channel;
• determine whether the first identification information is associated with information indicating that a retailer-specific or system-specific client application is installed on the first user device;
• and
• transmit, based on identifying a media targeted for the first user device, the media to the first user device via the wireless communication channel, wherein:
• the media hub device includes a printer associated with the point of sale terminal.