"Activewear is a category where women continue to spend, especially as there becomes increased acceptability of multiple wearing occasions beyond simply exercising," explains Kelly Tackett, a senior consultant at TNS Retail Forward.

Lululemon is not, by a long shot, the only retailer noticing the opportunity. J. Crew, American Eagle, Victoria's Secret, Gap, T.J. Maxx, J.C. Penney, and Wal-Mart are among the retailers shifting focus to activewear offerings through acquisitions or new product lines.

But analysts such as Howard Tubin, a senior analyst with RBC Capital Markets, see Lululemon as strategically superior to these players due to its premium image and product designs that are fashionable as well as technically sophisticated.

"Lululemon is one of a handful of retail apparel doing well right now," says Tubin. "The brand is unique, the grassroots marketing they do is unique, and the price point is relatively expensive, but people have continued to pay up for it."

Lululemon might remind you of another "lifestyle brand" that became a pillar of yuppie culture after pioneering the $4 latte; perhaps it's no coincidence that Day came to Lululemon after more than 20 years at Starbucks, where she served most recently as president of the Asia Pacific group.

But don't think Lululemon is Starbucks minus the stimulants.

While the Seattle-based coffee giant fashioned a global expansion plan based on turning out ubiquitous, carbon-copy outlets, the cornerstone of Lululemon's strategy is maintaining a local, distinct feel to each store.

Day says that the Lululemon values individualism over uniformity, an ethos which extends to each store's unique "community board" listing local fitness events to every outlet designing its own window displays.

Lululemon has rejected traditional advertising in favor of converting local yoga teachers, dance teachers, and running coaches in advance of a store opening to create buzz in the community. The retailer also hosts free in-store yoga classes and fitness clinics (including "dog yoga," no less) to help build consumer familiarity and loyalty.

Unlike many of its competitors, Lululemon has pursued an all-retail rather than wholesale approach, believing that the in-store experience and employing knowledgeable salespeople was integral to supporting the high price point.

"I learned from Starbucks to be really focused on the core of the brand and to make sure that you protect it at all costs," says Day. "At Starbucks, we kind of moved on to Frappuccinos and Caramel Macchiatos before we really owned latte. So sometimes innovation, while it can drive new customers, also takes you away from your core business."

Day stresses that while Lululemon's growth plans may seem aggressive, the near-term expansion goal is for just 200 stores in the U.S. and 45 in Canada—still small enough that the chain can continue to rely solely on affluent consumers.

Giving some credence to Day's assertions, shares of Lululemon have added 17 percent over the past month—perhaps the beginning of a full recovery, but that's still far from a sure bet.

Howard Tubin worries that in a period of rapid expansion, the retailer's necessarily time- and labor-intensive approach to opening new stores will be difficult to maintain. Lululemon's (appropriately) selective approach to real estate could also lead the retailer to fall behind with openings, putting pressure on current growth forecasts.

And even given Lululemon's promising strategy, analyst Tackett points out that the exodus to value stores is a very real trend even amongst high-income households—and one that could persist and worsen.

"We're increasingly worried that there will be fundamental shift in shoppers' preferences towards value-oriented retailers and brands," says Tackett. "Obviously the hope is that they come back when they have the money, but the concern is that the longer this goes on, the more entrenched the shopping behaviors will become."