Samsung uses OOH for real-time, two-way interaction.

To showcase the capabilities of the Galaxy Note 10.1, Samsung created an innovative live event in Portugal using a poster site which featured a remotely-located artist on a two-way digital screen. The artist was asked to draw caricatures of passersby in real-time. Those in front of the interactive billboard could watch the artist live on the giant screen as he drew their picture using the Samsung tablet. Afterwards, he revealed his drawings to the subjects, and the pictures were posted on Samsung Facebook page.
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Via: PSFK