Some celebrities can't seem to help themselves. Give them an opportunity, and they're prone to stick their name on a shoe, a sheet, even beef jerky.
Madonna is the latest big star to cash in on her name; in May she is set to launch a collection of sunglasses with Dolce & Gabbanna.
Dubbed MDG (for Madonna Dolce Gabbana), it's the first line of luxury accessories to come from Madonna's joint venture with Iconix, a massive brand management company that also owns the teen brand Candie's and Jay Z's Rocawear.
Madonna and her 13-year-old daughter, Lourdes, are also set to launch a teen fashion line called Material Girl for Macy's this fall. Lourdes, nicknamed Lola, designed most of the collection herself, Madonna told the Associated Press.
"I just stand in the background and go, 'That's cool, that's not cool,'" Madonna said. "She does have good taste in fashion. I respect her taste and I rarely disagree with her."
Fans and marketers have high hopes. With a reputation as a perfectionist who demands top quality from collaborators, Madonna has an advantage over other celebrities, ranging from Lindsay Lohan (sin: Ungaro pasties) to Jeff Foxworthy (sin: beef jerky), who have drawn laughs over their lines.
"Anything that Madonna touches does well," says Kristi McCormick, founder of Matchbook talent agency, which has represented celebrity chef Emeril Lagasse and football star Tom Brady. "Women, young and old, want to look like her, dress like her, be like her."
Madonna is tapping into a hot trend: celebrity product branding. It's different from endorsements, in which a star simply agrees to act as a spokesperson for a certain company. Celebrities who launch their own lines often come up with ideas for products themselves, help with the design and own a stake in the venture.
Not surprisingly, celebrities and business don't always mix, says Mark Roesler, CEO of the branding agency CMG Worldwide.
"Celebrities often think they have more power in the marketplace than they do, and they often get involved in projects that aren't well thought out," says Roesler. "It's a difficult business world out there and many products fail."
Sometimes stars stray too far from their base, branching into product lines that don't reflect their own tastes and don't appeal to their fans, says Roesler. Or they cash out too cheaply, putting their name on flimsy, overpriced merchandise.
"If the product is subpar, I don't care who has it, it's going down," says Gregg Lipman, managing partner at CBX Strategic Branding, who has advised such clients as Snapple and the Beijing Olympics. "A celebrity isn't going to save a bad product."
Plus, if the celebrity falls out of favor with the public, or becomes embroiled in a scandal, the entire line comes under attack.
Celebrity Brands: Lohan's Flop
Lindsay Lohan's stint as artistic adviser for haute couturier Emanuel Ungaro last fall, for example, turned into a big flop after Ungaro models walked down the runway flashing barely-there heart-shaped pasties. It didn't help that Lohan has been suffering from low credibility after a series of tabloid scandals.
Fashion critics slammed Ungaro for putting an embattled celebrity with questionable fashion credentials in control of a venerable luxury brand.
"Everything that Lindsay Lohan has done has been pretty unfortunate," says Adam Hanft, founder of the branding firm Hanft Projects. "When you're famous for being famous, it's more difficult to extend that ephemeral celebrity value you need for a more substantive brand value."
Successful celebrity lines typically have one thing in common, experts say: a clear correlation between the brand's attributes and the celebrity's values.
"As a celebrity you have to understand why people buy you, and what makes people come back to you again and again," says Andy Bateman, CEO of Interbrand, one of the world's largest branding agencies.
Justin Timberlake's fashion line William Rast, for example, is considered a hit because the singer "kept it simple" and "jumped on the denim bandwagon when it was extremely popular," says Marissa Rizzutto, a fashion designer who has made jewelry for pop star Fergie.
Experts say that Timberlake had already built a lot of good will among consumers as a credible musician and stylish dresser, so when he decided to launch a fashion line, he had some "brand equity" to cash in.
Another example is Sean Combs (aka P. Diddy), who started a joint venture with Ciroc Vodka. It works, says Bateman, because both the drink and Combs conjure up images of "a premium lifestyle."
"It wouldn't make any sense for him to do Budweiser or Coca-Cola," says Bateman.
That doesn't mean celebrities should only brand the kind of things they personally would use. Their daily budget, after all, often looks more like an average worker's monthly income. That's why many celebrities follow a strategy that combines the best of two worlds: bringing their luxury tastes down to a price that mass audiences can afford.
Celebrities As Fashion Mavens
This formula, which Bateman dubs "champagne at beer prices" has led to an explosion of celebrity branded products in recent years.
Fashion is the biggest market. Reality star Kim Kardashian has designed an entire line of slinky dresses for Bebe. Kanye West has designed an eponymous line of sneakers for Louis Vuitton. J Lo tried her hand at tight jeans for curvy women.
"Nowadays, it seems like every celebrity wants to design a line of clothing. Some are hits but most are misses, mainly because they know nothing about the fashion industry," says Rizzutto.
It's also impossible to walk into a perfume shop without stumbling over another celebrity fragrance. Just think of "Intimately Beckham" by former Spice Girl Victora Beckham and "Usher" for Him and Her.
Perfumes can be tricky, however, since fragrance is considered a very personal product. Consumers don't want to compromise their personality too much by taking on someone else's scent, says Julia Beardwood, founder of Beardwood & Company, who has worked with everyone from the model Iman to Calvin Klein.
Male fragrances, especially, can end up looking very tacky, she says, since men tend to be more conservative in their grooming choices. Beardwood says scents from Antonio Banderas, Donald Trump and Prince's 3121 are branding "don'ts."
"Many men like Prince but I don't know if they want to smell like him," she says.
Stars Like Sports, Food
Celebrities often also like to start their own food and drink lines. Comedian Jeff Foxworthy, for example, has launched a line of barbecue sauce and beef jerky, while Tiger Woods put his name on Gatorade's Tiger Focus -- which the company quietly discontinued around the same time Woods' sex scandal broke.
Sports is another big sector: Woods, Michael Jordan and Lance Armstrong have all made millions with their own sporting lines.
Why Celebrities Do It
There's little question why many celebrities go to the trouble of starting their own lines: money.
"I'm sure you and I would do it if we thought we could make a couple of million dollars by just putting our name on a fragrance," says Bateman. Companies who enter joint ventures with celebrities are often taking a gamble.
On the one hand, celebrities help products stand out: Madonna's name is likely to attract a certain segment of consumers, convincing them that those sunglasses -- more than hundreds of other styles that might be available more cheaply -- will give them a certain flair.
Plus, the media exposure that a celebrity can offer is priceless. When Iconix released news of its joint venture with Madonna, the company's stock price bounced about 1 percent.
But celebrity scandals can cost a brand dearly, if consumers continue to associate that brand with the star's indescretions.
"The question is whether all the Lindsay Lohan stuff is good for Ungaro," says McCormick. "Will people see the Ungaro name and only remember the Lindsay Lohan story, or is Ungaro later going to see the benefits of having had their name in the press?"