Is Barbie feminist? Is Beyoncé feminist? What about Game of Thrones, or Girls? Is smoking feminist? Or intimate waxing? Emma Watson? Spanx? Michelle Obama?

Questions of this sort have provided many headlines over the past few years. Whether celebrating the credentials of a well-known personality, film, or programme on tele­vision (“We need Kim Kardashian and her full-frontal feminism”), or pointing out sexism in popular culture (“The five most sexist moments in Jurassic World”), the online media have discovered that celebrity plus feminism equals clicks. The market is so crowded that it has become ripe for parody. In 2014 the spoof news website the Onion ran an article with the headline “Woman takes short half-hour break from being feminist to enjoy TV show”.

Andi Zeisler, who co-founded Bitch magazine in 1995, is among those who question whether the rising profile of feminism has resulted in better lives for women. She believed that pop culture could be used to spread feminist ideals throughout society. But even she was surprised when, nearly two decades after Bitch began, “Something weird happened: feminism got cool.” In 2013, Beyoncé sampled Chimamanda Ngozi Adichie’s Tedx talk “We should all be feminists”. Around the same time, Miley Cyrus declared that she was “one of the biggest feminists in the world”; then a Chanel runway show took the form of a faux-feminist rally. “By 2015, you couldn’t swing a tampon without hitting someone or something that boasted its feminist import,” Zeisler writes. “It was hot. And, perhaps most important, it was sellable.”

Zeisler’s new book, We Were Feminists Once, explores how feminism evolved from a radical fringe movement into something that is altogether softer and sexier, a kind of lifestyle brand. This is what she calls “marketplace feminism”: cool, fun and accessible, yes – but also decontextualised and depoliticised. Language that was intended to describe power relations between the sexes has become meaningless under the influence of PR, journalism and advertising. “Empowerment” applies to buying lipstick just as much as it does to changing the fundamental hierarchies of society. “Feminist” is now a label that is as marketable and coveted as Gucci or Chanel.

The culprit here is capitalism, which encourages us to believe that we can buy our way to happiness: marketplace feminism, in turn, encourages us to believe that we can buy our way out of oppression. But it is possible to be too fastidious about the corrupting influence of cash. Important feminist texts are profitable, from bell hooks’s Feminism Is for Everybody to Candace Bushnell’s Sex and the City. If Beyoncé’s album Lemonade made $3m a day, does that invalidate its artistry? This book retails at £17.99 – so is Zeisler simply profiting from feminism’s fashionable status? Clearly not. Being popular and commercially successful isn’t enough on its own to make any work or person a hollow symptom of feminism’s commodification.

Yet there is a serious issue about how a radical movement has been co-opted to flog TV shows, beauty products and even an internet provider (last year’s Virgin Media campaign featured a girl being inspired by clips of Billie Holiday and Emmeline Pankhurst). When mainstream feminism encourages us to believe that the political is only personal, it employs the neat trick of redistributing responsibility from structures to individuals. Worried about global warming? Take shorter showers. Concerned by the continued oppression of women? Feel empowered by having a feminist leg wax, or show your support with a slogan T-shirt. This emphasis on personal behaviours and consumption quietly displaces any need for ­organised political resistance. “Feminist” as a personal brand is a lot less threatening to existing power than “feminism” as a collective social movement.

There is some cognitive dissonance at the heart of this book. After asserting that a focus on individuals is unhelpful, Zeisler cannot resist weighing up the relative feminist credentials of Beyoncé (“undeniably powerful”), Amy Schumer (“problematic”) and Emma Watson (“well-meaning” but “off-key”). Her title, too, suggests an element of the personal: once upon a time, we were the real feminists, before the mainstream got its grubby little hands on our movement, before everyone else was feminist, before it became cool.

I and many of my peers know that accessibility and trendiness have their merits: if seeing cooler, older women self-identify as feminist encouraged me to do the same, that superficial approach was still a productive gateway to appreciating the more complicated and political elements of the movement.

But the content of Zeisler’s book suggests that simply identifying oneself as a feminist is a fruitless goal in any case. For her, the future of the movement depends not on “who labels themselves feminist”, but on “what they’re doing with feminism”. It seems wise to stay focused on that.

Anna Leszkiewicz co-hosts the SRSLY podcast and writes for newstatesman.com