SO, if girl power still exists, what is it? If the reports are to be believed, it's pocketing a whopping £50m from 17 London concerts and, at £75 a ticket, rubbing their hands at the prospect of another windfall from their three sell-out Manchester dates.
Of course the group maintain the motivation for returning hasn't been cold hard cash. And they insist they've come back up north after they missed the provinces on their last tour and found themselves bombarded with complaints.
Click the green play button on the right to hear an exclusive interview with the Spice Girls, starting with the group's memories of living in Kirkstall.
"We actually have to say a massive thank you for that," said Mel C, presumably addressing the north of England. "I told the girls all about it, Mel B was over in LA and I actually woke her up because we were so overwhelmed by all the emails we received trying to get us here."
"And it worked!" added Mel B.
The two northern members of the band are particularly pleased to be in this neck of the woods since they know Manchester's close enough to attract fans from Sporty's native Liverpool and Scary's home city of Leeds.
To see stunning photos of the Spice Girls, click here.
"I'd love to play Leeds," said Mel B.
"But we have a really big stage set up with this tour and we're reluctant to make the show smaller, so we need something as huge as Manchester Arena unfortunately."
And since they can fill a 21,000-capacity arena three times over, who could blame them?
But if girl power is the ability to make thousands of fans part with millions of pounds is it done by means of seduction or, as a cynic might suggest, a bit of a con?
For a start they are no longer girls, a fact which is obvious during the interview as they are sitting just a few feet away.
These are fully fledged thirtysomething women with a backstage creche and character lines to prove it.
Not that they don't look impressive. Although their appearances are often judged harshly – with Posh supposedly lauding it at the top and sporty languishing somewhere near the bottom in the aesthetic stakes – there's actually not much to choose between them.
Mrs Beckham may be famed for her skinny frame but even standing next to her none of the other band members could be described as anything other than svelte.
The overall verdict? Posh's harsh tilted bob is distractingly odd. Baby is the natural beauty. Ginger looks the oldest. Scary is indeed scary (and sexy) and Sporty unquestionably the most endearingly attractive.
To be fair, they've chosen to be interviewed in a dimly-lit room and since they're minutes from going on stage on their first night at Manchester they're all covered in a thick layer of make-up.
Pop lambs they ain't – but there's still no mutton in sight.
"When we get back on stage we're just children again, anyway," said Emma. "We might go backstage and feed our own kids but when we're out there it's just one big party.
"If anything having our kids with us actually adds to the sense of fun, there's a very playful, happy atmosphere going on all the time." said Mrs Beckham.
And, as if on cue, in walks Mr Beckham with their three sons, closely followed by Emma's boyfriend Jade and their five-month-old son Beau Lee Bunton.
David later makes an appearance at the gig walking hand in hand with Mel B's eldest daughter, Phoenix Chi.
They precede a young woman, possibly a nanny, carrying a little baby with a giant pair of headphones on its head. Could this be Angel, Mel B's daughter with Hollywood superstar Eddie Murphy?
All the journalists are warned not to broach the subject of the turbulent wrangles with her ex-partner. "Good reporters know which roads not to go down" was the line.
Several interviews in the States, where interest in the Murphy/Mel B stand-off is even greater, were apparently brought to an abrupt end when US hacks dared to go down that road.
We avoid it, not least because Mel B doesn't seem in quite as talkative a mood as the rest of the group.
Though the Leeds-born lass, raised largely in Burley and a pupil at Intake High School in Bramley, perks up when she hears her home city mentioned – so too, unexpectedly, do the other band members.
"Leeds has totally made me who I am today," said Scary. "Apart from being with this lot and travelling the world – your childhood experiences mould you completely."
It's at this point that Geri shouts a word you would never expect to hear come from her lips.
The other band members stare at her.
"Do you remember all of us sleeping in your bed in Kirkstall?" she continues. "It must have been 10 or 12 years ago, we were recording in Sheffield, we didn't even have a record deal then."
Then Mel B remembers: "Oh yes, it was my mum's house."
Geri said: "We were top-and-tailing in this tiny house in Kirkstall, mucking in together, eating chips and, erm, what do you call those things.....
"Scraps!" laughs Mel B.
"That's right, scraps, love those," said Geri.
"Oh and bread cakes!" chips in Emma.
Mel B said: "We didn't go out in Leeds though, it wasn't quite as happening 10 or 15 years ago as it is now."
"But I seem to remember we did have a great house party there," recalls Emma. "In fact it's great to be back up north.
"Do you know I think I've got more northern friends than I have southern friends?"
Geri said: "Totally! I think between the two Mels the north has had such a huge impact on my life."
Baby added: "Which is why we wanted to be here so much and it's great that we could come for all the fans who said they wanted us to."
"I really admire the northern determination – you tell us what you want and you get it!" said Geri.
Posh interjects: "In all seriousness though, the support you've shown all of us is fantastic and that's why it's nice to come back and say thanks. Personally I have such fond memories of living in the north."
On or off the stage, the Spice Girls are obviously consummate performers. Developed over years in the business, they can consistently wrongfoot reporters with a fearless charisma.
Like residents of tropical climes who have to constantly negotiate omnipresent flies, they're at once relaxed, playful and sometimes irritated by our intrusion. But they always accept our inevitable presence and deal with it.
Their main weapon is the obvious dynamic between the five. Sporty is their mainstay, Baby is quietly confident while Posh is amusingly loose-talking.
Interestingly Ginger is often prone to scatty blonde moments, in contrast to Mel B who seems quietly mocking, occasionally laughing at Geri throughout the interview. It's easy to see how (assuming the rumours are true) these two could clash.
So is this a facade of unity? Another part of a possible con?
Whatever it is, it works. As a unit – as a five-strong unit – hacks posing even the most awkward of questions somehow feel more nervous than the Spice Girls might feel having to answer them.
If there is any friction here, these pros are unlikely to let anyone exploit it.
In fact it's easy to get swept along in the flow of saccharin-sweet sentiment which glazes their comeback. Not least because it's hard to understand why, since all their dates are sell-outs, they actually need publicity-garnering interviews.
Perhaps, just perhaps, there is no con. Maybe it's all seduction and 75 is a fair price to pay. There's even a chance the group really are touring to say something to the fans and not merely to feed a cash cow.
"We've been asked about this time and time again," said Mel C. "But the purpose of this tour is to celebrate our past successes.
"We have no intention of continuing as a group and that's why we haven't released new material other than the two tracks on our greatest hits album.
"We're big fans of Take That and they're really deserving of their new success with their new stuff. But we don't want to follow that path; we're quite happy with what we've done."
Then Posh, with characteristic ineptitude, said: "I don't think the music industry is a very nice business to be in and, personally, I wouldn't want to be in the industry anymore."
This prompts a huge laugh from the rest of the band who perhaps can't believe she has just inferred what the Spice Girls do isn't, strictly speaking, music.
"What I mean is," she continues, "what we're doing now is more about just having fun and a laugh on tour with our families around us."
Mel C tries to retrieve the message: "The point is, it's very much about nostalgia. Also, we've seen our fans grow up and have their own children and there's a whole new generation of Spice Girls fans out there.
"Plus we've had the chance to appreciate it much more. Everything happened so quickly, so all-at-once first time around and we never thought about it ending.
"But now we know it can't last forever, so we enjoy every second of it."
And then, for any Spice Girls fan, comes the concluding body blow which suprisingly comes from Baby Spice: "We're taking each day at a time.
We're having a rest first and then going to see what happens because you never know what's round the corner.
"But our main aim in coming back was to celebrate the Spice Girls, give something back to our fans and say a proper goodbye."