Women pay $25 and men pay $55 just to get in, but pretty girls who out-dress the dress code are admitted for free. The door charge is mostly there to weed out people who won't spend on drinks, said nightlife baron Sean Christie, managing parner of another Wynn club, Surrender.When it first opened in 2008, XS was lucky to be filled halfway to its 5,000-person capacity, even when featuring an act such as Tiesto, the world's highest-paid DJ, according to Forbes, pulling down $250,000 a set and making $22 million a year. Now, the club may see 8,000 people come and go over the course of a night. That's nearly half of the capacity of Madison Square Garden. As the clock edged toward 2 a.m. on a Saturday earlier this spring, superstar DJ David Guetta stood at the control board like a mad king, commanding his people. A wiry, hollow-faced Frenchman with a curtain of blond hair, Guetta has been churning out electronic music since the genre's infancy in the world of underground raves 25 years ago. Now, at 45, he makes hits for pop music stars including Rihanna, Usher and Nicki Minaj â¿¿ and conducts the crowd at XS. At the flick of his upraised palms, Guetta had thousands of revelers whooping, jumping and punching their fists in the air. When he added a drumbeat into a chorus, metallic streamers dropped from the ceiling and a fog machine churned. "Nothing compares with this," said 23-year-old Katie Kelly, a student in San Louis Obispo, Calif., as she bobbed her index fingers skyward. "You just release and don't care about anything." XS boasts that its layout is modeled on "the sexy curves of the human body." In practice, the design steers people to the bars on a back wall. Female bartenders, their long hair draped over sequined black corsets, serve $15 shots of Jack Daniels whiskey, coordinating their pouring to the skull-rattling bass and synthetic blares vibrating around them. A supermarket a few miles away sells a bottle of Jack containing 17 shots for $16.