At the 6th Annual L’Oréal Paris Women of Worth Awards, L’Oréal introduced Julianna Margulies as its latest brand ambassador for Women of Worth, a nonprofit that recognizes women making a difference in their communities. When The Good Wife actress spoke to the audience, it was clear she truly believes in the cause and the remarkable achievements of women who are trying to make the world a better place. At that moment, I couldn’t have cared less if Margulies is a celebrity; her belief in this charity was all that mattered.

Growing up, I also adored the partnership between Isabella Rossellini and Lancôme. I often pored over print ads featuring Rossellini, one of Lancôme’s longest-running spokespeople, and I recalled her face as I browsed through the brand’s products. I was much younger than the Rossellini target market, but that didn’t prevent her involvement from have a strong impact on me.

But do all brand ambassadors have the same impact?

J.C. Penney recently appointed Ellen DeGeneres as its brand ambassador, much to the chagrin of loyal customers. This is because in the end, brand ambassadors often do more than just sell the product they represent. They create identities that impact the way consumers view the brand. In this case, some of consumers felt DeGeneres represented a shift that was outside their comfort zone.

Beauty connoisseur Nicole Gordon Levine loves ambassadorial associations. “My favorite is Andie Macdowell, as she has been a wonderful representation at every stage of her aging process,” she explains. Macdowell is a L’Oreal Paris brand ambassador. But Gordon Levine laments the lack of creativity in brands seeking out these partnerships; they could, for example, more often feature makeup artists when campaigns are launched.

The advent of social media also gives individuals a platform to voice their opinions, and often those opinions are trusted more than celebrity endorsements.

And for some, it doesn’t matter if there is an ambassador at all.

“When it comes to beauty,” says Maria Russo, editor of The Culturist magazine, “I’m only concerned about the ingredients. The company could have Julia, Sophia, and Emma collectively trying to sell me a product, but if the ingredients are not organic and naturally extracted from the earth, I’m not going to pay it any mind.”

What do you think? Do celebrities make the best brand ambassadors, or do the consumers?