America is partying down with Paris Hilton and Nicole Richie.

The duo's Fox reality show, "The Simple Life," (search) snared 13.3 million viewers in its second airing Wednesday night - an increase of 200,000 viewers over its Tuesday premiere.

The show, which plunks Hilton and Richie into a backwater Arkansas town, also won its demos across-the-board, gaining 12 percent in adults 18-49 and a whopping 24 percent in adults 18-34 over its Tuesday opener.

"The Simple Life," coupled with "The O.C." and "That '70s Show," keyed Fox to a nightly win in adults 18-34, persons 12-34 and teens.

Richie, meanwhile, will make her first late-night talk show appearance on CBS' "Late Late Show with Craig Kilborn" this Monday.

Hilton famously backed out of a recent scheduled appearance on CBS' "Late Show with David Letterman" - angering Letterman, who took out his wrath on Hilton's publicist in his nightly monologue.

Richie is the daughter of pop songster Lionel Richie, and Hilton is the heiress to the $360 million Hilton hotel fortune.