Since the US launch of Dyson vacuum cleaners in 2003, they have taken the US market by storm. In fact, Dyson has been so successful ? not just in the US, but throughout the world - that Hoover, once the powerhouse of the vacuum cleaner industry, has rapidly lost market share. In fact, Hoover has experienced such a decline in profitability that it has been put up for sale by its parent company.

But how has Dyson achieved this success? Is it due to superior design and functionality or is it the result of a slick marketing campaign? The real question is this: how sustainable is Dyson's success? Marketing hype is OK in the short term, but can cost you down the line if customers do not become repeat buyers because they feel cheated by the initial sales pitch. On the other hand, if the Dyson range really does deliver, then customer loyalty will no doubt ensure long-term success.

After much hard work and thousands of prototypes, James Dyson unveiled his first vacuum cleaner - the G force ? back in 1991. He'd tried to take the Dyson concept to all of the major players in the industry, but was politely shown the door at every turn. With a lack of funding to turn his dream into reality, he was facing bankruptcy. However, he caught a break by winning a Japanese design award and soon the G-Force was selling for $2,000 a pop there. This gave him the cash flow he needed to set up on his own and the popular DC01 model was launched in the UK in 1993. It was an instant smash hit and it took on the mantle of being the best selling vacuum cleaner in the UK within 2 years.

Engineering and good design definitely played a hugely important role in the success of the Dyson. The Cyclone technology is at the heart of the Dyson concept, the claim being that there are no bags or filters to clog up and so there is no gradual loss of suction, as is experienced with traditional vacuum cleaners. Usability is also key and the Dyson is brimming with ergonomic features. The DC05, for example, is designed to balance solidly on your stairs. The latest Dyson, the DC15, is the subject of 182 patents and 3 years of R&D investment and offers ?The Ball? technology. ?The Ball? replaces the wheels and makes it easier to manoeuvre the vacuum cleaner around your house, around furniture and into nooks and crannies. No more back and forth, pull-push manoeuvres, now you can twist and turn!

On the other hand, all of this gadgetry comes at a price. Not just a monetary price ? which is a significant factor - but the reliability of the Dyson range has been called into question. With all of these interacting parts and design features, it is little wonder that a 2004 survey by consumer magazine Which? placed Dyson vacuums at the bottom of the pile in terms of reliability. However, and perhaps counter-intuitively, the same study reported that Dyson users were most likely to refer the product to a friend! Could it be that a lack in long-term reliability is offset by a truly superior product that delivers on its marketing messages?

And talking of the marketing messages, Dyson undoubtedly has a great campaign. Much of its initial success was built on the clear-chamber ?bagless? concept. As it turns out, the fact that people can see the dirt being extracted from their furniture and carpets is enough to make them buy an expensive vacuum cleaner? especially when they are encouraged not to store it away in the back of a cupboard because of the bold color scheme and futuristic exterior styling (think iPod or iMac for vacuum cleaners!) The Dyson really has been positioned as a trendy design statement. But who would have known? Far from being marketing genius (although it was) the campaign was built around the engineering and usability strengths of the product. Because the Cyclone technology delivers maximum power without degradation over time, it will pick up more dirt. The clear-chamber ?bagless? concept was driven by a passion to demonstrate the power of the product, rather than as a marketing gimmick ? it just happened to be a stroke of genius!

For all its success the jury is still out on how the Dyson will fare in the future. The time when customers start to think about replacing their existing Dyson will be make-or-break time in terms of the company's future. But despite some concerns over the reliability of their machines, it seems that customers like what they see in the Dyson range of vacuum cleaners and believe that the Dyson is a superior product.