Women everywhere cheer when we hear a brand is no longer going to airbrush its models. After all, none of us look like the women we see in the advertisements that grace the pages of fashion magazines, so it's reassuring and image-boosting when we find out that no woman looks like that – not even the woman in the photograph.

Recently aerie, the label under which American Eagle (NYSE:AEO) sells underwear, bras, and other apparel to young women, unveiled a campaign where its models will no longer be airbrushed. Without the aid of Photoshop, the "aerie Real" campaign features models wearing bras from size A to DD instead of the industry standard B cup in every photo, and woman are reminded, "The real you is sexy."

With less fanfare, American Apparel (NASDAQOTH:APPCQ), revealed a somewhat different ad just days later on Facebook, saying, ""Sexy has no expiration date." Instead of the focus being on a model's size, however, the ad featured a 62-year-old lingerie model.

It seemed like every woman with whom I was associated on Facebook and Twitter was discussing these ads with excitement those first few days. After the ads are revealed and get their 15 minutes of fame and applause, however, do they actually benefit the brand?

The forerunner for the 'everyday' model

Aerie and American Apparel are not the first brands to attempt to reach consumers with more "everyday" looking women. Unilever (NYSE:UL) brand Dove was perhaps the first to dive headfirst into the trend with its "Real Beauty" campaign launched a decade ago. Over the years we've seen Dove feature women who look more like us, our sisters and mothers than fashion models.

It worked in the beginning, too. Dove increased its sales by 600% in the first two months following its first use of everyday women in ads, according to Ben Barry, whose modeling agency was involved in the Dove Campaign for Real Beauty. But some warn Dove is an example of how "cause marketing" can have a short lifecycle.

Saj-Nicole Joni, chief executive of Cambridge International Group, authored a piece for Forbes in which she argued Dove's campaign peaked quickly and then flat-lined. Although she says sales jumped by 20% overall for the company in 2005 following the campaign's launch, sales flattened by 2006. She points out that in 2007 the brand returned to selling based on, "features, segments, and new products," and by 2010 the campaign was "softened" as it became, "The Dove Movement for Self-Esteem." Although Dove continued the campaign in some form or another, it was no longer the centerpiece of its sales strategy.

Fashion designer Karl Lagerfeld is quoted in a feature Barry wrote for fashion magazine Elle Canada as having said, "Unreachable beauty is a reminder to make an effort. But if you see something, and you can reach what you see, then you do not have to make an effort anymore."

Barry also includes a more blunt comment from professor and researcher Naomi Mandel: "It's better to use extremely thin models because that's what makes women feel bad about themselves and want to buy the products."

I reached out to Mandel to get her thoughts on the current situation with aerie, and she had this to say: "I suppose it depends what they mean by 'no longer airbrushing.' If they are still going to use thin models, but those who are not impossibly thin, I suppose it can only mean an improvement to women's self-esteem. But does raising self-esteem sell products? It will be interesting to find out."

Making a connection, but does that mean a sale?

Lagerfeld and Mandel hit on the real question: do women say one thing and then turn around and use their credit cards to support something else entirely?

It's perhaps too early to tell, as the movement toward using more everyday-looking models is still somewhat in its infancy. Both Dove and Barry have some results that might show Lagerfeld and Mandel are wrong.

Last year, Dove's "Real Beauty Sketches" became the most viral video of all-time. Although the video wasn't about selling Dove's products, its popularity shouldn't go unnoticed.

Barry also wrote his doctoral thesis on whether models of different age, size, and ethnicity could benefit brands, and his results are somewhat contrary to the belief held by Lagerfeld, Mandel, and many others in the advertising and fashion industries.

Barry's research was funded by the Ogilvy Foundation and involved women ages 14 to 65 who wore dress sizes from 0 to 18 and represented a range of ethnicities. Study participants were shown mock ads that featured models all wearing the same dress, but who differed from one another in age, size, and ethnicity. Would women prefer the most attractive models, even if their look was unobtainable, or would they prefer the model who looked most like them?

Here are some of the results:

  • Overall, women in the study increased their purchase intentions by 200% when the models in the mock ads were their size.
  • For women over a size 6, they increased their purchase intentions even more dramatically, by a whopping 300%, when the ads featured curvier models. The opposite was true when the model didn't reflect their size, decreasing their purchasing intention by 75%.
  • In good news for the American Apparel ad, women over the age of 35 increased their purchase intentions by 200% when they saw older models.

Barry concluded that models of all sizes and ages can be effective. "Their effectiveness depends on whether the model shares the consumers' traits," he says.

Models as role models

One thing brands and magazines are finding is that few people share the traits of too-skinny models. SELF, a health and fitness magazine, has admitted to airbrushing models to look, "bigger and healthier," and a former editor of Cosmopolitan has said, "Our magazine was all about sexiness, glamour, and curves. We knew our readers would be repelled by these grotesquely skinny women, and we also felt they were bad role models and it would be irresponsible to show them as they really were."

Some countries have even passed laws against too-skinny models. For example, Israel passed a law in 2012 known as the, "Photoshop Law," that prevents underweight models. The law is enforced by requiring women who want to be models to obtain a medical report no more than three months old that states her BMI is above the World Health Organization's standard of malnutrition. Under that standard, a female model who is 5-foot-8 couldn't weigh less than 119 pounds.

Few believe a law like that will be forthcoming in the United States, but more brands and magazines seem to be jumping on the bandwagon and abandoning the skeletal model look. Certainly more brands will join if companies like aerie and American Apparel can link sales success to the campaigns. So, ladies, if you want to keep seeing models who look more like you, show your support with more than just your social media account.

Kristi Dosh has no position in any stocks mentioned. The Motley Fool recommends Unilever. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.