This is the [artist id="501686"]Britney Spears[/artist] we all remember. Thanks to better-than-expected first-week sales of more than [article id="1601037"]505,000 for Circus[/article] and strong initial ticket sales for her 2009 tour in support of the album, Spears is adding a number of dates to the outing, dubbed "The Circus Starring Britney Spears."

According to tour promoter AEG Live, more than 400,000 tickets have been purchased to date for the North American shows that were just announced last week, leading to the addition of six more dates -- in Los Angeles; Toronto; New Jersey; Chicago; Long Island, New York; and Anaheim, California. The North American tour is slated to launch on March 3 in New Orleans and run through late April.

The singer has also added six more nights to her June residency at the O2 Arena in London, where more than 100,000 tickets have already been sold for what will be Spears' first arena tour in five years. That brings her total number of tour dates to 42.

"Britney and I are both thrilled to see how excited her fans are for the Circus tour," Spears' manager Larry Rudolph said in a statement about the tour, which will also be featuring [article id="1600903"]opening act the Pussycat Dolls[/article]. "This show will blow people's minds and promises to show Britney's fans something they will never forget!"

Dates for the Circus Starring Britney Spears:

· March 3 - New Orleans, LA @ New Orleans Arena

· March 5 - Atlanta, GA @ Philips Arena

· March 7 - Miami, FL @ American Airlines Arena

· March 8 - Tampa, FL @ St. Pete Times Forum

· March 11 - Uniondale, NY @ Nassau Coliseum

· March 13, 14 - Newark, NJ @ Prudential Center

· March 16 - Boston, MA @ TD Banknorth Garden

· March 18, 19 - Toronto, Ontario @ Air Canada Centre

· March 20 - Montreal, Quebec @ Bell Centre

· March 23 - Uniondale, NY @ Nassau Coliseum

· March 24 - Washington, DC @ Verizon Center

· March 26 - Uncasville, CT @ Mohegan Sun Arena

· March 27 - Pittsburgh, PA @ Mellon Arena

· March 30 - Houston, TX @ Toyota Center

· March 31 - Dallas, TX @ American Airlines Center

· April 2 - Kansas City, MO @ Sprint Center

· April 3 - Minneapolis, MN @ Target Center

· April 6 - Edmonton, Alberta @ Rexall Place

· April 8 - Vancouver, British Columbia @ General Motors Place

· April 9 - Tacoma, WA @ Tacoma Dome

· April 11 - Sacramento, CA @ ARCO Arena

· April 12 - San Jose, CA @ HP Pavilion

· April 14 - Salt Lake City, UT @ EnergySolutions Arena

· April 16, 17 - Los Angeles, CA @ Staples Center

· April 19, 20 - Anaheim, CA @ Honda Center

· April 22 - Oakland, CA @ Oracle Arena

· April 24 - Glendale, AZ @ Jobing.com Arena

· April 25 - Las Vegas, NV @ MGM Grand Garden Arena

· April 28, 29 - Rosemont, IL @ Allstate Arena

· June 3, 4, 6, 7, 10, 11, 13, 14 - London, UK @ O2 Arena