It's nearly 30 years since the word "cyberspace" first appeared in print, in a short story by William Gibson for the July 1982 edition of the now-defunct science fiction magazine Omni. In an interview in this summer's Paris Review, Gibson describes, not for the first time, how he came up with the word: "The first thing I did was to sit down with a yellow pad and a Sharpie and start scribbling – infospace, dataspace. I think I got cyberspace on the third try, and I thought, oh, that's a really weird word. I liked the way it felt in the mouth – I thought it sounded like it meant something while still being essentially hollow." The trajectory from Omni to the Paris Review says less about the way Gibson has changed in the intervening years than about the way science fiction has, both in itself and in terms of its status in the wider culture – in large part thanks to Gibson's nine novels. The last six of them – Virtual Light (1993), Idoru (1996), All Tomorrow's Parties (1999), collectively known as the Bridge trilogy, Pattern Recognition (2003), Spook Country (2007) and Zero History (2010) – have recently been reissued by Penguin in a new uniform edition. Gibson's influence is evident in everything from the Matrix movies to Jennifer Egan's A Visit from the Goon Squad, which won this year's Pulitzer prize for fiction.

Gibson is widely credited with having predicted the rise of the internet, but doesn't himself have any delusions about his prophetic powers. "The record of futurism in science fiction is actually quite shabby," he says in the Paris Review. "Novels set in imaginary futures are necessarily about the moment in which they are written. As soon as a work is complete, it will begin to acquire a patina of anachronism."

Cyberspace, as Gibson imagined it nearly 30 years ago, was – or would be – a realm of total-immersion virtual reality: when Case, the hero of Neuromancer (1984), applies the dermatrodes of his cyberspace deck to his forehead, powers it up and jacks in to the matrix, his "inner eye" sees a "transparent 3D chessboard extending to infinity", on which, or in which, is "a graphic representation of data abstracted from the banks of every computer in the human system". The idea came to him from watching kids playing arcade games – "it seemed to me that what they wanted was to be inside the games, within the notional space of the machine" – and an advertisement at a bus stop for Apple computers. "Everyone is going to have one of these, I thought, and everyone is going to want to live inside them. And somehow I knew that the notional space behind all of the computer screens would be one single universe."

In Gibson's most recent novel, Zero History, a thriller set in the here and now, there's a scene in which one of the main characters, Milgrim, is sitting in a hotel lobby in London, "trying to grasp Twitter", which he is supposed to use as a covert and anonymous way of communicating with a US federal agent. "He was registered, now, as GAYDOLPHIN2. No followers, following no one. Whatever that meant. And his updates, whatever those were, were protected." Milgrim's confusion is partly down to his being in recovery from a 10-year addiction to prescription tranquillisers, but everyone – at least, everyone over the age of 12 – who's joined Twitter must have had similar feelings the first time they logged on. The confusion aside, the banality of it all is a very long way from jacking in to the matrix through an Ono-Sendai Cyberspace 7 deck. "The strongest impacts of an emergent technology are always unanticipated," Gibson says in the interview. "You can't know what people are going to do until they get their hands on it and start using it on a daily basis, using it to make a buck and using it for criminal purposes and all the different things that people do." (Gibson, who tweets as @GreatDismal, came 37th on Time magazine's list of the 140 best Twitter feeds.)

The most striking feature of cyberspace in Neuromancer, however, the most radical way in which it differs from the modern internet, is its textlessness. Case is, or may as well be, illiterate: his skills as a cyberspace "cowboy" don't depend on being able to read. He wouldn't get very far as a hacker these days. The internet, as we now know it, even in the era of YouTube and podcasts, is still heavily text-based and text-dependent. Tweeting not only looks about as low-tech as you can get, it's also all about language. Yet in another sense, Neuromancer's cyberspace is text-based, or text-generated, because Neuromancer is a novel. One of the attractive contradictions of good science fiction is that its speculations about the technology of the future are recorded and transmitted in a medium that's been around for centuries, the old technology looking to the new without either deference or condescension.

Gibson is as interested in old technology – the ways it persists, the ways it becomes obsolete, the ways objects outlast their functions – as he is in the latest gizmo. Zero History's point of view alternates between Milgrim's and Hollis Henry's. Hollis used to be the singer in a band called the Curfew; she's now a freelance writer. She, like Milgrim, first appeared in Gibson's previous novel, Spook Country (2007), in which it's pointed out to her by a Belgian advertising tycoon called Hubertus Bigend that "in the early 1920s … there were still some people in this country who hadn't yet heard recorded music … Your career as a 'recording artist' … took place toward the end of a technological window that lasted less than a hundred years." It finished, Bigend says, once consumers of recorded music were able to produce it themselves.

In Zero History, Hollis and Milgrim visit Paris on assignment for Bigend. He wants to know who's behind an achingly cool, incredibly hard-to-come-by line of clothing. "Gabriel Hounds" is a "secret brand": it has no advertising, no marketing, not even a regular supply chain. Every so often there'll be a small sale at a market in Melbourne or a boutique in Soho, jealously guarded knowledge of which is spread beforehand by word of mouth. It's hardly surprising that Bigend, as an advertising man, should be curious about a brand that's simultaneously so invisible and so sought after. But his interest in Gabriel Hounds may also have something to do with another of his projects: he's thinking about getting involved in supplying the US military with clothing and other kit. And the people whose turf he's muscling in on aren't happy about it.

Bigend's firm, Blue Ant ("We aren't just an advertising agency … We do brand vision transmission, trend forecasting, vendor management, youth market recon, strategic planning in general"), has bought Hollis a Gabriel Hounds denim jacket, for an exorbitant price, from a dealer in Amsterdam. But bribery isn't the reason, or not the main reason, that she's working for him. She also needs the cash, having lost pretty much everything in the credit crunch.

Milgrim, too, works for Bigend because he feels he has no choice. He's been cured of his addiction at an experimental Swiss clinic and given a new set of teeth, all at Bigend's expense but none of it out of the goodness of his heart: for one thing, he was curious to know if the Swiss clinic's methods were effective; for another, Milgrim has a remarkable eye for detail, which Bigend finds useful. In return, Bigend looks after Milgrim and keeps him supplied with his rehab medication.

Bigend makes a habit of recruiting anyone more than half-interesting who crosses his path. In Pattern Recognition, Cayce has been brought to London to give her opinion on a new logo for the world's second best-selling brand of running shoes. She has an unusual gift: she is, for want of a better word, allergic to branding; the stronger the brand, the worse her reaction – the first time she saw the Michelin Man, as a child, she was nearly sick. This makes her invaluable as a marketing consultant. After she gives the new trainer logo the thumbs down, Bigend makes her another, less conventional proposition. Cayce is a fan of "the footage", an abstract film that's being uploaded to the internet in short segments, which appear unannounced and at unpredictable intervals in various quiet corners of the web, "somewhere where it's possible to upload a video file and simply leave it there". (The novel, set in the late summer of 2002, was published in February 2003, more than two years before the first video was uploaded to YouTube.) Bigend wants Cayce to track down the maker of the footage. Cayce agrees, not least because she'd like to know who's behind it herself, and sees that with Bigend's resources she may be able to find out. It's also, in Cayce's head at least, complicatedly bound up with the disappearance of her father, a retired spook last seen heading towards downtown Manhattan on 11 September 2001 (the Los Angeles Times recently called Pattern Recognition "the first – and still, in many ways, the best – book of fiction to emerge from the tragedy"). But one of the things that Cayce and Bigend both value about the footage, though for very different reasons, is that it has (so far) defied commercial exploitation; Bigend's involvement will necessarily change that – he's late capitalism's answer to King Midas, though unlike the mythical Phrygian tyrant he's more than happy with his status.

"We've arrived at a level of commodification that may have negated the concept of counterculture," Gibson says in the Paris Review. "Consumers don't buy products so much as narratives," Bigend says to Hollis, elaborating on what he means when he talks about "brand vision transmission". She tells him the idea's old (which it is, though the rise of the ebook gives it a literal new twist), and he concedes the point. "Once you have a way in which things are done," he continues, as if this were the line he'd wanted to take all along, "the edge migrates". In an interview last year, Gibson described Bigend as someone "who presents himself as though he knows what's going on, but who in fact doesn't … he's bullshitting himself". Which is clearly true, and the way he talks is a finely judged send-up of vacuous marketing-speak. But at the same time there's no denying that Bigend is very successful, very rich and very powerful. The "edge" that he's most interested in is the edge of his own sphere of influence. He seeks out whatever lies just beyond it and finds a way to incorporate it, and in that way his sphere of influence expands.

Strictly speaking, Pattern Recognition, Spook Country and Zero History aren't science fiction: the technology in the novels isn't speculative but already exists; the world they're set in is recognisably the world that we live in. Gibson explains that they are "attempts to disprove the distinction or attempts to dissolve the boundary. They are set in a world that meets virtually every criterion of being science fiction, but it happens to be our world … It has, to my mind, the effect of science fiction." And, in common with science fiction, the books explore what happens when a trend – technological, sociological, environmental, political – is taken to its logical conclusion.

If the Sprawl in Neuromancer and its sequels is a fantastical extrapolation of late 20th-century urban development, so Bigend is a fantastical manifestation of some of the mechanisms of late capitalism. He isn't merely a very successful brand marketing consultant; he's brand marketing personified. When Cayce first meets him in Pattern Recognition his smile is described as "a version of Tom Cruise with too many teeth, and longer, but still very white". As supervillains go, he's disturbingly lacking in malevolence, and chillingly banal. Then there's the matter of his ridiculous name, which as well as making him sound like a remnant of the 1970s porn industry carries more than a hint of apocalypse. One of his current enthusiasms is the "order flow": "the aggregate of all the orders in the market. Everything anyone is about to buy or sell, all of it. Stocks, bonds, gold, anything … If someone were able to aggregate that, the market would cease to be real." And Bigend, last seen on a giant hovercraft heading for Iceland, may be about to crack it.

To order any of the six new Penguin resissues of Gibson's novels (RRP£8.99) for £7.19 each with free UK p&p go to the Guardian bookshop.