It seems only a blink in time ago that Web 2.0 was being talked about, though just what it was remained, and still remains, something of a mystery, being one of those internet terms whose meaning shifts depending on who’s talking, and at what conference of internet seers.

But boiled off to its essence, Web 2.0, an idea dating back to 2004, meant and means an internet of zippy connections where surfers can actually interact with one another, the epitome being, of course, YouTube or MySpace.

That’s opposed to what came before, Web 1.0, if you will, though no one calls it that, in which folks were happy to read content and send emails.

Now comes Web. 3. 0. It’s a term heard more and more these days as the new, different thing, a huge advance on 2.0.

And, as with 2.0, the term is more disputed than discussed, with all manner of definitions being tossed about.

In some ways that make sense. Looked at broadly, Web 3.0 is everything the internet will become once it achieves Web 2.0. Describing Web 3.0 is like describing the house of the future or the car of the future. It’s whatever the speaker wants it to be.

Which is why a lot of internet people back off from the discussion entirely.

“Web 2.0 is a goal that we haven’t even come close to reaching yet,” says Richard Townsend, digital media strategist for Circus Street Communications in London. “For marketers to start to think about Web 3.0 would be misleading.”

Yet that said, there is a growing consensus of what Web 3.0 will be, and perhaps the best way to describe it is as an intelligent internet universe. Think of it as a seamless network of databases that interact with great fluidity and have the capacity to not just crunch data but to interpret it.

Imagine databases that can learn, computers that can read web pages and understand them.

It’s what folks are calling the semantic web (from the Greek sémantikós, to have meaning).

But there are many other notions floating about regarding Web 3.0.

“Masses of people, including vendors, technology proponents, analysts, bloggers and authors, are trying to use the Web 3.0 term to suit their needs and visions,” observes the Gartner Group, the consulting outfit. So far, it counts at least five different ideas out there. More are expected.

“The name Web 3.0 is just a holding page for the technologies to come,” says Jean-Paul Edwards, head of media futures at OMD UK Group. “We will never get to Web 3.0 because when the development comes, we will call them something else.”

What are advertisers to make of this?

As Edwards sees it, the next big thing will be predictive targeting. “Ultimately the advertising in Web 3.0 will be for things that you don’t realize you want yet,” he explains.

Agrees Emily Riley, advertising analyst at Jupiter Research: “Behavioral targeting exists today, but it will continue to evolve. This could include some form of predictive modelling, which is something that agencies are modelling today.”

In essence, predictive targeting would be about gathering information on where a person goes online and analyzing it to the end of anticipating that person's likely next purchases. For instance, a person visiting parenting sites could become a target for new car ads. After all, a growing family might need a bigger car.

As Townsend explains it, it would be like the second or third generation of the way sites like Amazon now make individual recommendations based on what the consumer has viewed in the past. “Ultimately it is about integrating information more easily,” he says.

But in Web 3.0 it could also happen that advertisers turn to targeting machines, rather than people.

Why machines? Because, as Edwards explains, it may come to pass that people begin assigning some of their purchasing decisions to their computers.

For instance, they could entrust a computer avatar to scout the net for the best deal on all the household cleaning products and then have the avatar negotiate the price and make the buy.

Indeed, Edwards sees brands potentially spending significant portions of their ad budgets targeting these avatars. “For marketers there will be enormous changes.”

Another big change to come for advertisers is how they go about finding their audiences, and it promises to be a great deal trickier than today.

Consumers are going to be viewing the world across three screens – the mobile, TV and computer. And they are going to be watching what they want, where they want.

Content creators will attach sponsorship or advertising to the actual show, rather than to a particular channel. Says Riley: “They’ll need the right ad for the right piece for the right person."