Celebrities serving as spokespersons and ambassadors for beauty companies isn’t anything new. Co-owning the company though is becoming a popular endeavor, and why shouldn’t celebrities gain on the brand recognition their face brings to a company?

Jennifer Aniston took the hair care plunge last October when she became the face and co-owner of Living Proof, the Cambridge, Mass.-based company that uses technology deriving from MIT research in its formulas. The company said it saw a spike in sales in the days following the announcement of the partnership.

“She’s already impacting the business. Having this major hair icon love your products has helped us get brand awareness. We have a very loyal—but—small following. The biggest opportunity was brand awareness, which was very low, especially on a global level,” said Jill Baraud, CEO of Living Proof, earlier this year.

Katie Holmes’ announcement that she was becoming a co-owner of luxury hair care brand Alterna followed shortly after Jennifer’s news, and already her presence has generated large brand awareness to specialty retail partners such as Ulta and Sephora, along with influencing salon sales.

“Since that time, we’ve doubled our business in Sephora, which is where she’s had the most impact,” said Joan Malloy, CEO of Alterna. “And we’ve maintained a healthy double digit growth as well. A year ago we had a 500,000 PR impressions. With Katie we have over a billion.”

To keep the brand awareness rolling, the John Barrett Salon, which occupies the ninth floor of Bergdorf Goodman, has committed to carrying Alterna products, and also hosted a party on October 9 for the 34-year-old actress to celebrate their two new dry shampoos; Sheer Blossom and Mango Coconut – Katie’s favorite. “It smells like coconut cake and who doesn’t like that?” she said.

Dressed in a fitted navy dress, Katie exuded a true paradox: an air of girlish shyness mixed with a wholesome sophistication. Surprisingly tall, she is soft-spoken, charming and welcoming, with beautifully full, healthy hair – of course—that gracefully falls over her shoulders.

Katie is also the brand ambassador for Bobbi Brown, and is a co-founder of fashion label Holmes & Yang, which launched in 2009. Yes, the ex-Ms. Cruise has been busy.

“The quality of the products is so high. They’re free of parabens, sulfates and phthalates,” Katie explained. “I’ve tested them out and they really work. I believe in the integrity of the company and I like being part of something that’s providing products that are good for you.”

Created in 1997, Alterna prides itself on being the first luxury hair line to introduce anti-aging hair care products, a CC caviar cream and a scented dry shampoo collection.

Last year, prior to Katie investing in the company, Joan read an article on the actress in Elle magazine and felt a deep kinship between her and what her company embodies.

“She represents a natural luxury and an authentic quality that’s synonymous with our brand,” Joan said. “I felt she was inspirational in what she stood for; a young, single mom who was transforming her life. Our customer is that person. Stylish and discerning.” According to Joan, Katie will have a strong voice in the decision making process as she comes from a consumer point of view.

Joan joined the company four years ago and was quick to implement what she calls the three P’s: people, product and placement. First a new leadership team was put into place. Then, key innovations were inserted into new products, which were followed by a multi-channeled brand distribution. “Then we needed to put a face and voice behind the brand,” she added. Enter Katie, who ironically was moving to New York from Los Angeles at a time when Alterna was relocating to New York from the West Coast also. The company signed her at the end of 2012, and an advertising campaign rolled out this past March.