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Studio Audience from WikiPedia:

A studio audience is an audience present for the taping of all or part of a television program. The primary purpose of the studio audience is to provide applause and/or laughter to the program's soundtrack (as opposed to canned laughter). A studio audience can also provide volunteers, a visual backdrop and discussion participants. On some game shows, contestants are taken from the studio audience, such as with The Price Is Right.

In some cases, a studio audience can be called upon to vote, to help a contestant (such as with Who Wants to Be a Millionaire) or pass judgment on a politician, for example.

In the United States, tickets to be a part of a studio audience are usually given away for free as opposed to being paid admission. As an enticement to attend, one or more members of the audience may be selected to win a prize, which is usually provided by a manufacturer in exchange for an advertisement, usually at the end of the show.

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