In XCrawl, you can grandstand to the crowd or mug for the camera during a dungeon crawl. There are a lot of rules around that - Perform skills, etc - but it seems like the only effect I can find is a long term Fame bonus if you make 5 successful checks. Does it have some other effect, Mojo bonuses or the like?
The bonus of fame IS the bonus. It is added to various non-performance rolls outside the dungeon-arena. Fame also affects one's appearance fees. (P.122)
So the whole point of grandstanding is to get your fame up by making the crowd like you. Which, by the way, makes it easier to please the next crowd.