As Doreen Dignan, managing partner at MindShare Insights, says: "Most people realise that people behave less and less like others of the same age or sex, but more and more like people who have the same attitudes and interests."
Nevertheless, while the gender lines may be blurring, research does point to the fact that traditional male and female approaches are strikingly apparent in certain media.
Christina Hartley, group ad marketing director at IPC Media, commissioned a study earlier this year to explore attitudes to TV-listing magazines. "We didn't think there would be a gender difference. But it was interesting how stereotypical men and women still are," she says.
Findings showed that typically task-oriented men went straight to the listings to find out when sport was on. Women were more emotional, reading the features and making appointments to view shows.
"Both sexes are more complex," says Hartley. "We have more choices for everything from media to leisure. There aren't any barriers for anything anymore."
That's why this list of five key female consumer groups is so diverse. It encompasses women who are putting their own interpretation on the traditional housewife role, as well as those who are desperately trying to accept the role modern society has thrust upon them.
These "Single Income No Boyfriend and Desperate" women have seen Bridget Jones numerous times but don't take any comfort from its happy ending. Rather than grimacing at the "smug marrieds", this group watches them with feverish envy. They desperately want the engagement ring, the kids and the mortgage that all their twentysomething friends around them seem to be acquiring.
Justin Gibbons, head of strategic insight at PHD, was shocked by their honesty when he spotted this group through his work on understanding single women for clients such as BT and Harvey Nichols.
"We thought Bridget Jones had given women the confidence that it was all right to be single. But these women were desperately unhappy, despite the media spin justifying this lifestyle," he says.
Media telling them that being single is fun won't resonate. "It's not enough to punt Bacardi Breezers at these women," says Gibbons. Media that gets through to them is of the more introspective type, like new magazine Psychologies - which will explore why they feel like they do, and how they can cope with their situation.
Rather than shiny, happy sitcoms such as Friends, they'll be tuning into dark psychological dramas like Lost and its ilk. As for radio, they prefer to listen to nostalgic tunes on Magic rather than Johnny Vaughan on Capital.
While the tag "Yummy Mummy" may have been around for a few years, only now is she really coming into her own. This woman was very career-oriented before she had kids. As a result, she uses many of the tools of the workplace to organise her domestic life. The school run, for example, is time-managed with military precision.
Pre-children, she derived status from her job title. Now it's her family that she puts on display like a fashion accessory. And, boy, will this family look the part.
"This is a group which has driven the trend in the past few years for pop-culture kids clothing and now we're seeing them drive a new trend for dressing kids up in traditional clothes," says William Higham, founder of Next Big Thing.
Higham says you'll probably find the average Yummy Mummy has a copy of Junior magazine poking out of her designer buggy. She also has a penchant for upmarket women's glossies and food titles. She doesn't have time for TV, preferring the internet.
They're also quite a spiritual bunch. Think Gwyneth Paltrow with her yoga mat. "Spirituality, well-being and relaxation are important to this group. Advertisers could reach them by acknowledging this spiritual side. As for tone, they should give them the facts and let them make up their own minds," says Higham.
NOT SO DESPERATE HOUSEWIVES
The internet has opened up a whole new world to these mothers. They use it to manage the household finances, buy their new vacuum cleaner or the weekly groceries and help their kids with homework.
Doing chores online gives the Not So Desperate Housewife more time to do what she enjoys most - surfing the net for pleasure.
In a typical day, she spends three hours online. She's become so adept at using the internet's many resources, that she'll often listen to the radio, watch TV and read newspapers or magazines via her PC. You'll also find her buying CDs, clothes and holidays via her trusty PC, as well as keeping in touch with other family members via e-mail.
Starcom identified this group while researching female attitudes to the internet. "To these women, the internet's a very positive medium too. They feel entertained, relaxed and satisfied by it. It's their media Prozac," says Mazelle Siton, senior consumer strategist at Starcom.
Clearly, online is a great way to reach this group. But be warned, in the mornings she tends to be in a very chore-oriented mindset so will only be interested in practical products like financial or household goods. In the evening, she's more relaxed and open to thinking about buying her next pair of shoes.
There are now 700,000 business women in the UK - a jump of 43% since 2000. The majority of them are aged 20 to 34 and single. Over a third live in the Greater London region.
As well as earning more than £60,000 per year in many cases, they have a high propensity to spend, with a soft spot for luxury toiletries, cosmetics and perfumes.
"She's independent and she spends the money she earns. She hasn't got much time to herself so the best way to reach her is probably through channels like e-mail," says Russell Budden, media analyst at BMRB.
Cinema is also a good media channel, as they're 87% more likely than the average to go to the cinema.
Alison Drummond, Carat Insight's research director, believes working women fall into three main mindsets, identified via the agency's Consumer Connection Study.
The first Drummond calls "soft success". She's driven at work but doesn't want to compromise her social life and values financial success.
The second is the "socially stressed" business woman. She struggles to combine work and her hectic social life. Media in pubs and clubs will reach her.
Lastly, the "living stressed". She feels there is never enough time to do work and home chores. Their routine, of which TV plays a big part, is the only thing that keeps them sane.
The word "alpha" in this group's title naturally prompts you to compare this woman with the more established Alpha Male. But, says Laura Simpson, acting head of McCann-Erickson's Pulse, this woman is not a Maggie-Thatcher-esque ball-breaker. "She isn't trying to be a man," she explains. "She's proud of her femininity. She's at the forefront of female emancipation, in a positive way."
This woman is likely to be in her thirties, pretty, intelligent and funny. She might have a toy boy on her arm. Or a man she's happily supporting financially. She's probably putting off marriage and kids, but isn't worried a jot about the ticking of her body clock.
While she's got a high disposable income from a high-flying job, she's hard to influence via advertising because of her strong will.
She enjoys reading women's glossies but will decide herself what is fashionable and will not appreciate being dictated to by brands. The Alpha Female is more than comfortable mixing her Prada with her Primark.
"You have to be selective in terms of when you talk to her," says Simpson. "The more personalised you can make the contact, the better. Tailored online marketing would be good, for example."
The Alpha Female's health and appearance are important to her and, despite a busy work schedule, she always manages to go to the gym.