A television commercial called “An open letter to the armpit” features several women in white tank tops taking turns reading a letter. “Dear Armpit,” begins the spot, which is directed by Pam Thomas and was introduced in January. “In the lottery of life, you drew the short stick. People shave you, pour hot wax on you, and your name is ‘armpit.’ People don’t treat you like skin because frankly, they don’t think of you as skin.”

After the product is shown, the women continue, “You can be a softer, smoother, more beautiful little armpit — you deserve our best care ever, and don’t you ever forget that.”

Print ads and billboards will also take the form of a letter written by Dove.

“Dear Razors,” says a print ad in the issue of People magazine that comes out on Friday. “Sixty-four percent of what you remove is hair. Thirty-six percent is skin. You should be ashamed of yourselves.” Another ad, addressed to Merriam-Webster, features a woman with her armpit proudly displayed, and asks in reference to one of the dictionary’s definitions, “Does this look like ‘the least desirable place’ to you?”

Dove, which declined to reveal expenditures for the campaign, spent $26.9 million on deodorant advertising in the United States in 2012 and $33.3 million in the first nine months of 2013, according to Kantar Media, a unit of WPP.

On Feb. 13, the brand held what it called PitiCure events in New York, Los Angeles and Miami, where women were guided through a process of swabbing underarms with an exfoliating cloth, rinsing and applying Advanced Care deodorant.

Despite the economic downturn and few nonusers to lure into the category, the deodorant market has grown steadily, with revenues increasing 9 percent in the United States from 2008 to 2013, according to the market research firm Mintel. Unit sales have been flat or down, but for so-called clinical strength varieties, which have higher concentrations of anti-wetness active ingredients, brands are charging about twice as much as for their regular deodorants.

Dove’s new Advanced Care line splits the difference — consumers will pay 20 to 30 percent more than they do for the original line, but not as much as they do for Dove clinical-strength offerings, which cost twice as much as the original line.