Really? (Skinnygirl Facebook page) Really? (Skinnygirl Facebook page)

Last month, the booze empire Beam reported that sales of its Skinnygirl line of diet wines and vodkas had tanked, diving 26 percent in 2013 -- even while the rest of its portfolio did 2 percent better on average than the year before. You might chalk that up to poor ratings for the brand's main backer, Bethenny Frankel, whose talk show was canceled in November after just one season. But it's more likely that Bethenny wasn't the problem: Diet liquor just doesn't have much appeal.

"People don't drink alcohol for health and wellness reasons," says Spiros Malandrakis, a senior alcoholic drinks analyst with the consultancy Euromonitor. "Sometimes with marketers, navel gazing can become so much of a problem that you forget about how people go out and drink."

The more successful strategy, Malandrakis says, is to emphasize the positive qualities a drink brings to the table -- more flavor, more personality, rather than fewer calories. And in particular, don't try to target specifically women.

"Whenever gender-specific roles are underlined, it tends to backfire, because it's seen as patronizing," he says (certainly the case with Skinnygirl's "Drink like a lady" tagline). Another case in point: Molson Coors' Animée, a pink-colored beer that was supposed to "make beer a real choice for women who are vital in growing a shrinking beer market" by dispelling "the perception among women that all beers look and taste the same," which the company saw as an "exciting opportunity to break down the barriers between women and beer." The product did not catch on.

It's true, of course, that Americans have long sought to cut calories through consuming "light" beer -- but that segment has been losing steam faster than most, as drinkers move into craft brews with higher alcohol contents. And besides, beer is something you might actually drink in large quantities. Vodka, on the other hand, is difficult to consume in the kind of volume that might make somebody fat in the first place. Meanwhile, wine is already supposed to be good for you, and the diet version just tastes bad.

"No wine blogger that respects himself would write good words about such products," Malandrakis says.