Ireland attributes her success to her methodical approach to expansion. In fact, her first foray into the business was socks. She wanted to see how something simple would sell before she rolled out swimwear, active wear and other items a year later in 1994.
"If women would embrace something as basic as a pair of socks, that would tell us we were on to something," says Ireland, who sketches looks for her line for a design team to refine.
More recently, singer Jessica Simpson, 32, has built her brand into a billion-dollar brand in the past seven years. She now sells more than 29 products from shoes, clothes and perfume to purses and luggage in department stores such as Macy's. For the winter holidays, items include $89 platform bright blue platform pumps and $128 strapless belted lace dresses.
Her formula for success has been having a relatable personality: Even as her singing career has wavered, branding experts say Simpson has been able to connect with her young fans because she's vocal about everyday issues like her struggles with weight gain.
Peggy Merck, the publicist for the brand, also says she's very involved in designs for the line, which reflect her casual but sexy style. Her collection, which ranges from size 2 to 16, features lots of cowboy boots, vintage jeans and wedge shoes. Simpson is "hands on," Merck says.
Simpson's business savvy has inspired other celebs. "I admire Jessica Simpson a lot because she has branded her line to become a huge success," wrote "Jersey Shore" reality TV show star Nicole "Snooki" Polizzi in an email to The Associated Press.
Polizzi last year started selling perfume and nail polish, among other items at HSN home shopping network and to beauty chain Perfumania. This fall, she expanded her collection to include jewelry. She also plans to add headphones and accessories next year.
"I bring in my ideas on what type of bottle shape I'd like, to different designs of animal print or clothing designs to my favorite smells from soaps, lotions (and) hair sprays," Polizzi wrote.
BEYOND THE NAME
Attaching a star's name to a tee shirt or earrings does not guarantee success. Generally, how well a line does varies greatly, and depends on a number of factors, including the star's popularity and involvement in the design, the quality of the merchandise and the marketing of the brand.
There are all sorts of ways celebrity lines are started. But in many scenarios, the idea of starting a collection comes from the celebrity, who shops the concept around to manufacturers and stores. How the deals are structured varies widely.
The lines can be a gamble for stores. For one, their success often is closely tied to one person whose popularity can fade quickly among finicky fans. And while shoppers may grab celebrity brands when the lines debut, they may not return if they don't like what they see after that.
"The celebrity name draws the fan base to the product but at the end of the day, the product has to stand on itself," says Michael Stone, president of The Beanstalk Group, a global brand licensing agency. "It has to be well priced and well designed."
Indeed, industry experts say for every celebrity brand that is a hit, five others flop. Anyone remember hip hop star and actor L.L. Cool J's casual clothing line with Sears? It lasted less than a year after its launch in 2008. One reason was that the collection of hooded sweatshirts and jeans failed to catch the eyes of Americans at a time when the country was in a deep recession.
It's also key that the clothes reflect the personality of the celebrity because many consumers will want to emulate their style. For example, Lopez, 43, shuttered her Sweetface clothing collection in 2009, six years after launching it at several department stores, in part because shoppers didn't believe that the line matched her glam style. The collection, which included sweat pants instead of the fitted dresses Lopez is known for sporting, was seen as too casual.