No, I'm just looking before I buy it online

High street retailers are starting to wince.

People just aren't coming through the doors with the enthusiasm and open wallets they used to. The response - to drum up business with advertising - is interesting, principally because it's being targeted at the online world.

The Internet Advertising Bureau reckons that online spend will double from 2004 to the end of 2006; though Guy Phillipson, chief executive of the IAB, added that "the traditional retail sector is largely unready to reap the benefits of e-commerce and online advertising."

You can say that again.

It seems to have escaped British retailers that people frequently now use the Net as the start and end point of retailing, with a middle bit that might involve dropping into a shop and handling the merchandise in order to make a decision, which is then fulfilled at home or work via a screen.

I'd say that's certainly behind the problems at Dixons Store Group, which saw a fall in profits despite rising sales, and same-store sales dropping (if only marginally).

But online advertising isn't necessarily going to be the answer, unless it's very cleverly done. What the retailers really need is a better understanding of online search, so that people looking for (say) DVD recorders can find them quickly.

The problem for retailers is that they've had hundreds of years getting used to the way people buy things in the real world. Some scientists have devoted their lives to finding better ways to track how we make decisions in shops.

And now that's all being torn up, because when we shop online, we do it differently.

You want a DVD recorder. You're in front of a computer. Do you think "Hmm, Dixons sells those, I'll go to their home page"? Nope - you slam your query (perhaps with a target price) into a search engine and see what comes up. (There's a Dixons store only five minutes walk away from where I'm sitting, but I'm not going to go there. I've got a column to write!)

The result is the equivalent of visiting all the shops in the high street simultaneously. With the internet we've brought Star Trek's transporter to life, and discovered that it's not particularly good news for the places we visit. Rather like Captain Kirk's intrepid bunch, we look, but don't interfere with the life we find there.

(OK, I exaggerate somewhat. High street retailers aren't on the edge of extinction. But they want growth, not stagnation. And while inflation might be only a couple of per cent, business rates, service charges and other costs are rising much more rapidly than RPI.)

Things are hotting up on the online shopping-search front, though. Besides eBay's purchase of Shopping.com, AOL in the US has done a deal with the Yellow Pages there. In the UK of course Google has linked up with our home-grown Yellow Pages, and launched the UK version of Froogle back in October. We're spending billions online that we weren't spending in shops, and it isn't all going to organisations that used to run shops.

Meanwhile the Scripps organisation, one of those old "newspaper" groups, has spent half a billion dollars buying Shopzilla - which also has a UK arm. Everyone wants to be right in there, winning your clickthroughs. That hasn't been overlooked by the analysts at Jupiter Research, where the chief executive Alan Meckler (who held a big search engine conference in London earlier this month) comments that "Search has turned out to be the killer application of the internet. And clearly Search is only at end of its beginning."

Yes, but this beginning stuff is tricky, even though the principles should be glaringly obvious: shoppers want depth, but also relevance.

So let's do some shopping. If I ask Froogle UK for "DVD recorder £200" then I get a brace of choices for those machines at around that price. If I ask Shopzilla UK the same question, it only offers me one model. Ditto for Shopping.com (which aliases me to uk.shopping.com, which is fine). That's one up to Froogle. I wouldn't shop in a store that only had one product; afterall, we have left the Soviet Union behind.

I asked Kelkoo as well, and only got one model - plus a long listing of DVDs with titles like "200 Cadillacs".

At which I realised my mistake - or rather, their mistake. All but Froogle ignored the £ sign I'd typed in.

Result: Froogle gets the clickthrough.

It gets even worse if you try searching for "PVR" - an abbreviation for "Personal Video Recorder", which I've always seen treated as a synonym for "Digital Video Recorder", which most people think only exists as a Sky+.

Nope - some places will know what you mean, some will offer you plug-in cards for your computer.

So I think it's great news that high street retailers are going to start advertising online some more.

But I've got a warning for them, and the search engines that will take their money: you'd better start understanding your customer really well, or the market domination by retailers like Tesco will look trivial. Winner doesn't have to take all online - but it can easily turn out that way if you're not watching what your customers do.