Grocery retailer Morrisons must hate my wife and I. We are what the Americans refer to as 'barnacle shoppers' - that is, we often call in on our local Morrisons [it's on a route we commonly take] and buy only items that are on a two-for-one offer.

As any business and/or marketing student and/or practitioner will tell you, these offers are 'loss leaders' - those known value items [KVIs] that are meant to attract customers into the store where they will then spend hundreds of pounds on their monthly grocery 'shop'. So when we turn up and buy only the special offers, Morrisons would be better off having someone meet us at the door, give us £10 cash and show us back to our cars - for they are loosing money on our every visit [to be fair, we do occasionally complete our monthly shop at a Morrisons store, and hey are my favourite of the 'big four']. Of course, ushering customers away from your store is not seen as good customer service - no matter how good the practice is in business terms.

Similarly, in B2B environments, there are also bad customers. These are the ones who always expect preferential treatment, faster deliveries, shorter lead times, longer invoice dates and better discount rates. They also buy very little. Then they return half of the goods as 'faulty'.

In both of these scenarios it takes a brave sole to take the decision to turn away these customers - and then you have to do so in a way that does not damage your reputation. In B2B it is relatively easy, a quiet chat can do the trick - and what's more your 'good' customers will probably appreciate your actions. But having security staff turn away customers at the entrance to your shop is not a good plan.

And so to the point of this musing. Online, you can 'put off' those unwanted customers - and they will never know you are doing it. Providing you have some kind of log-in or registration facility - or just cookies might work - you can track the online behaviour and buying habits of individual customers. And if they are 'bad' you can make their visits - how should I say this - not a good experience. How? What about bombarding them with pop-up ads for products they have no interest in? Or move them onto a [very] slow server so that the pages download oh-so-slowwwwwlllllyyyy.

Can't say I have ever spoken to an organization that admits to doing this, but anacdotal evidence would suggest it is already regular practice. Have I ever experienced it? I don't think so ... but then the Morrisons site did seem a bit slow, and what would I do with an annual subscription to 'Knitting World' magazine? OK, so I'm kidding about Morrisons.co.uk - but maybe my broadband connection isn't the reason for some slow e-commerce sites that are full of pop-up ads. What do you think?