Britney Spears' cumulative concert merchandise sales reached more than $30 million during the first leg of her North American Onyx Hotel tour, the highest total for a solo female artist in that time span.

The $30 million total is based on Spears tours since June 1999, including 1999's Baby ... One More Time tour, 2001's Oops ... I Did It Again tour and 2002's Dream Within a Dream tour as well as the first part of the Onyx Hotel tour.

The Onyx tour alone, which begins its European dates today in London, is expected to gross more than $10 million in merchandise revenue.

In the 25 tour dates of the North American leg, Spears' merchandise sales averaged $150,000-$170,000 a night, reaching a high of $180,000 during the Los Angeles show March 8, according to Dell Furano, CEO of Signatures Network Inc., a leading merchandising and licensing company that handles Spears products.

"Many times what happens is, as your audience ages, you still can sell tickets and albums, but your merchandise sales will start to decline," Furano said. "With Britney, as she's gone to an older audience, her audience is still as passionate about her. Ultimately, merchandise is a reflection of the passion they feel for the artist and the show."

Spears' demo in 1999, and the average demo for pop artists, is ages 8-14. Furano said this demo usually has the highest per-head purchase power because most often it's the parents who take their kids to shows and stand in line to buy merchandise. Spears' average audience for the current tour is 16-24 and leaning toward the female side, Furano said. She also has a strong gay fan base.

"Now there aren't parents going to the shows, unless they're just a fan," Furano said. "It's late teens and young twentysomethings that are going to the show and are buying the merchandise for themselves because they just think Britney's cool. This is about a cool factor."

Spears' best-selling products include the pink "Toxic" baby-doll shirt, the Onyx Hotel fashion jersey and tour programs and posters.

"I think part of it reflects her songs like 'Toxic' and 'Outrageous,' " Furano said. "A lot of the merchandise picks up themes of the songs and of the show."

Merchandising also is becoming many music stars' answer to lackluster record sales.

"The world of the record royalties and significant earnings from records is down dramatically," Furano said. "That reflects three things: Artists need to tour to promote record sales; revenue from ticket sales are very significant to the income stream now that record sales are down; and merchandise. Britney Spears is going to gross over $10 million (for this tour), (and) half of that she'll end up putting in her pocket."

Signatures Network also handles the merchandise for Madonna, who Furano said "breaks sales records every night" while touring. The main reason why Spears' sales figures over the past five years are higher than Madonna's is because Madonna has only toured once in that period versus Spears' four outings.

Signatures Network holds worldwide merchandising and marketing rights to more than 125 top music artists and entertainment properties, including Bruce Springsteen, U2, the Beatles, Jessica Simpson, Ozzy Osbourne and Tim McGraw.