Urban Dictionary says:

Rent a crowd
(Un)cool soicialites wearing tacky skirts and an ugly hats, paid heaps for just turning up
the (infamous)Hilton Sisters Melbourne Cup 2003


2. Rent a crowd
Wankers who will protest against anything and everything even if they don't know what they are protesting about. Mostly made up of foul smelling hippies and moronic people

3. Rent a crowd
One person who can make as much noise and do as mush damage (usually in a drunken state) as a crowd of seven or eight people.
James 'rent a crowd' O' Brien is some loud messy bastard!

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