There was once a fashion for “built-in obsolescence” that caused a high-tech product to break down after a few years, forcing the customer to buy another one. Happily, the firms who followed that fashion got such a bad reputation that they had to change or die.

Instead, we now have “obsolescence by proxy”, which forces the customer to buy an updated model, even if his old model is still working well. The increase in computer speeds, for example, makes it very difficult to use the internet with a ten year-old computer.

The most widespread “obsolescence by proxy” is the deliberate restriction of supplies necessary to use old technology. Buying a paper roll for an old fax machine or a blank tape for a VHS recorder or an ink cartridge for an older printer can be so difficult that the customer buys the new technology out of sheer frustration.

Yet many customers like their old technology. Geeks who work in high-tech businesses should not assume that everyone shares their obsession with having the very latest model. Some cannot afford to upgrade every few years. Others have the money but resent spending it on a new system when their existing one is doing the job perfectly well, thank you. Those who are comfortable using their familiar technology are reluctant to start learning the quirks of a more complicated system. Those with a lot of video tapes on VHS do not welcome the time and expense of transferring their collections to disc.

The need to transfer data from “floppy disc” to CD format has been a major inconvenience to many businesses. The low storage capacity of the “diskette”, and the fact that new computers no longer have inbuilt drives to insert it, put it in the bed next to the door some years ago. They have been absent from most shops for some time now, and Sony has finally announced that they will cease selling them. Yet many people and businesses would still like to buy them.

It is a perfect example of an increasingly common situation, in which the big manufacturers have a vested interest in “obsolescence by proxy” – but in which smaller entrepreneurs have a golden opportunity. Providing supplies necessary to operate “redundant” technology may be a massive growth area in the years ahead, especially if the big manufacturers persist in their strategy of trying to make redundancy faster than ever.

There is an instructive precedent in the history of vinyl records. They have been redundant in technological terms for many years now, and were effectively driven from the high street shops by the CD – but there remains a huge market for them. Much of the money to be made from technological progress can be made by defying it.