In 2002, Clay Shirky wrote "In-Room Chat as a Social Tool", where he described trying A Really Simple Chat in a meeting. Projecting the chat page in the meeting room provides different types of interaction with the room than audio speaker-to-many or questioner-answerer interactions provide.

While someone was speaking, people accumulated comments and questions in the chat room without interrupting the speaker. The logged discussion allowed people to point out things for later consideration, without having to interrupt the speaker's presentation merely to share a point with the group.

Obviously, the chat tool's whispering abilities have different effects than whispering in a room.

He does say that they used physical red/green cards in the room... and people would wave green cards when agreeing with something in the chat room.