Ian Mann: Trout and his ex-partner Al Reis wrote the marketing classic, Positioning: The Battle for Your Mind 30 years ago, and it was named one of the 100 best business books of all time.

But much has changed since then - customers are savvier, competition is fiercer and communication is a thousand times faster.

Nowadays, we are being bombarded by an endless stream of messages from more quarters than ever, and we just cannot cope with it all. Over-communication has changed the whole game of communicating and influencing people. What was overload in the 1970s has turned into a megaload in the new century. So it is little wonder that our minds need simple, clear messages, just to cope.

The "best way to enter minds that hate complexity and confusion is to oversimplify your message", says the author. "Repositioning" is the act of adjusting people's perception of our business, and needs to be considered more frequently by all businesses. The term "repositioning" originally referred to something negative about your competitor as a way to create a positive idea about your product. The Republicans hung the label "flip flopper" on John Kerry to reposition the Bush administration as a more consistent choice. When Stolichanaya vodka hung the "American-made" label on its US competitors who were "making believe they were Russian", it was setting up Stolichanaya as "the Russian vodka". The process is well illustrated by the problem faced by Spain regarding its olive oil. Few people know that Spain is the truly dominant producer of olive oil - producing half of the world's supply. Italy produces only half as much and buys much of its oil from Spain, then bottles it and sells it with an Italian name. Spain needs to reposition itself and the solution suggested by Trout has three steps.

Step one is to clearly position Spain as the No1 producer of olive oil. This little known fact needs to be positioned in the minds of customers to provide their olive oils' credentials.

Step two is to dramatise this message by borrowing a historical fact and using this in the advertising message: "Two thousand years ago the Romans were our best customers. Today, they still are."

Step three is enabling people to find Spanish oil easily. A seal could be pasted on every bottle of oil, stating: "100% olive oil from Spain".

Repositioning your business by advertising alone is never successful. Nor is telling people "we value your business, please wait for the next available consultant" and you wait for so long that you can only conclude you are not valued enough for them to be adequately staffed.

Marketing involves the whole business and all its processes. The Granite Rock Company was selling rock and sand to local contractors. Renting trucks to move large quantities of construction material costs a dollar or more a minute, making the time it takes to load up important. The company developed an automated loading system similar to a bank ATM. It accepted an identification card, released the material, and printed a receipt, reducing loading time from 24 minutes to seven. Their repositioning as GraniteXpress, the quick supplier, was ensured because the experience backed the message.

When times are tough there is always the temptation to reduce the price of the product or service. Coach, an upmarket leather wear company, was faced with falling demand for their $300 handbags. Rather than dropping their price, it launched a new sub-brand, the "Poppy" line, which sells at 20% less than the original Coach bag. This avoided price-cutting which would only devalue a solid and established brand.

The author is a firm proponent of not lowering a price point as there is only one way from there on, and that is downward. When you are selling luxury, you are selling exclusivity. By telling the customer that they can buy the product for less, it loses its exclusivity.

Repositioning your brand is a slow process and as such requires commitment and patience. A clever, new advertisement repositioning the product when you notice your quarterly sales are down is a waste of your money and effort. The general rule after you have attended to the product and processes is publicity first, advertising second. A linear programme is required with the elements unfolding over time.

Quicksilver, the surf and skateboard clothing brand, was faced with the sort of problem most companies want - they were selling so well through small surfing retailers that they were sure they could evolve to the bigger stores and increase sales significantly. But the company's founder said "Big is the enemy of cool" and this is a cool youth brand. Positioning and repositioning requires commitment from the top because it requires boldness and often some pain. While Trout is saying nothing that hasn't been said before, the book is nevertheless a good read.