Gaga ooh la la: Billboard projects that at its conclusion, Lady Gaga's worldwide Monster Ball tour—her first major stadium show—will have grossed nearly $200 million worldwide. The North American leg of her tour hit Boston, New York, Toronto, Dallas, Houston, Los Angeles, San Jose, Vancouver, Edmonton, and Philadelphia this summer. The pop star generated such a demand for tickets that after she hops overseas for the European leg of her tour, she'll return stateside in early 2011 to play North America again. "Ticket sales worldwide demonstrate that people are really excited to see the show … Over the course of the next many months we're trying to play to as many people in as many places as possible," said Arthur Fogel, chairman of Live Nation Entertainment’s global touring division. "It's an across the board home run."