A trade expo runs a speaker programme that maybe a fifth of the visitors ever sit down for. The rest are walking the floor when the session they wanted was on.
DSD supplied both halves: the stage and screen for the sessions themselves, and a freestanding touch kiosk so the programme, the exhibitor list and the session content are available to everyone else at the moment they are actually standing there.
One is scheduled, the other is on demand. Between them the programme reaches the whole floor rather than the seated fifth.