Multimedia advertising screens engage people in ways that static media types just can't. What's missing is the sound.
Whether your screens show pictures, animations or live video, involve passers-by further by allowing them to hear professional quality audio. If your content is interesting enough people will choose to more actively watch what's on offer... more so if they can hear it too.
LimeOnAir, paired with a simple WiFi access point (hotspot), is all you need.