Sunday’s Los Angeles Times Magazine marked a milestone: at 170 pages, it is the fattest Sunday magazine ever published by the Times.

It also is the result of an unusual marketing partnership between the paper and the Staples Center that points up some of the ways in which L.A.’s new sports facility is not only promoting itself, but providing deep financial benefits to its corporate sponsors.

The Times is one of a dozen sponsors that ponied up millions for assorted Staples Center signage rights, as well as other benefits. Sunday’s magazine was one of those perks.

The magazine focuses entirely on the new L.A. arena, with articles on everything from the history of the deal that put it together, to maps of the arena’s layout and stories about the food offerings inside. Many of the advertisers are the key sponsors of the arena: the Kings, Lakers and Clippers, Staples Inc., the arena itself and even the concessionaires.

Tim Leiweke, president of the Kings and Staples Center, referred to the magazine as a joint venture between the arena and the Times, though Times spokesman Mike Lang dislikes that characterization. “There was no involvement by Staples in this editorially,” Lang said.

It’s a sensitive subject because the Times has been criticized for initiatives from Times Mirror Co. CEO Mark Willes that have blurred the lines between the paper’s advertising and editorial departments.

The arena’s involvement was to contact the teams, concessionaires and various corporate sponsors and ask them to buy ads in the Sunday magazine; the ads themselves were sold by the Times’ advertising department.

“This is one of the benefits of being a partner with the arena,” said Kurt Schwartzkoph, director of marketing and promotions for the Kings and Staples Center. “We try to look at the sponsorships as more than just sponsorships. We look at it as, how can we help our sponsors generate revenues outside of Staples Center?”

Other newspapers, including the Orange County Register, the Daily News and La Opinion, also published special sections on the arena but they were done independently.

The newspaper blitz is only one component of the marketing effort taking place in the days before the arena opens. In all, Staples Center is spending about $1 million on P.R. and advertising this year, according to Leiweke, though when the cost of the various pre-opening events is added on, the total marketing tab is closer to $3 million.

As marketing budgets go, however, it’s pretty cheap. That’s because most of the promotional support the arena is getting is free.

“I’d say our marketing strategy is to build the best arena ever built. People are going to walk in and be blown away,” Leiweke said. “At the end of the day, we let the building speak for itself.”

Well, the building plus the Boss.

New arenas nearly always open with a big, non-sports event. Staples managed to land one of the biggest ever a four-day concert stand by Bruce Springsteen. On Oct. 1, a new sports arena in Denver opened with a concert by Celine Dion, and a few weeks earlier an arena opened in Atlanta with a show by Elton John but Springsteen is expected to out-draw either of them.

“If you have a huge season-ticket base already, and you open with a sports event, there are only a limited number of new people that you’re going to get in the building, because the ticket holders are going to go anyway,” said Steve Sander, president of Denver-based sports marketing firm Sander GBSM. “Plus, you want to get the kinks worked out in things like your food services before you bring your season-ticket holders in.”

Events like the Springsteen concert and the Democratic National Convention to be held at Staples next year not only bring in new people, they generate tremendous free media coverage.

Also expected to draw plenty of new people and media attention are major events running through this coming weekend, culminating with what is likely to be one of the biggest block parties downtown L.A. has ever seen.

All this week, radio personalities and other media figures are getting private tours. The real marketing extravaganza starts Saturday.

The day will start with an invocation by Cardinal Roger Mahony, a ribbon-cutting by L.A. political figures, and a daylong party featuring live music on two stages and culminating with fireworks and a concert by Chris Isaak. All of it is free, and the public will be allowed to tour the arena from 10 a.m. to 2 p.m. Between 30,000 and 50,000 people are expected to attend.

After the public tours are over, the arena will host a black-tie fund-raiser for the Staples Foundation, a charitable organization that supports sports and the arts in the inner city. The gala at the arena will feature performances by the Los Angeles Philharmonic and singer Natalie Cole; tables go for between $10,000 and $25,000 apiece.

“The nature of sports is very self-serving,” Sander said. “At least if you turn around and say you’re using the building to raise money for charity, you can generate a lot of goodwill in the community.”

For all the free publicity, Staples Center is spending some money on advertising. The ads are an effort to sell the remaining premium seats and luxury suites. They consist mostly of newspaper ads, as well as some spots on local news radio stations and bus signs.

Assistant Managing Editor Dan Turner writes a weekly column on marketing for the Los Angeles Business Journal.