Women are Ryanair's most loyal customers and more than half of the people who fly with the airline do not use rival low-cost operators, according to new research carried out by the University of Ulster.

The study shows that customers choose to fly with Ryanair for three key reasons: price, convenience and frequency.

The study, carried out by Prof Dolores O'Reilly and Ms Sharon Ponsonby, research assistant, both from the School of International Business, shows that, despite not offering inflight services, most passengers are happy with the "Ryanair experience".

Their report, based on interviews with Ryanair management, including chief executive Mr Michael O'Leary, and a random selection of 434 passengers, reveals an airline which, according to Ms Ponsonby, breaks the rules of Irish corporate marketing.

The study discovered that most of Ryanair's UK and Irish passengers learned about the airline by word of mouth or billboard advertising.

Ms Ponsonby said the airline's often confrontational marketing may not be typical but it had helped Ryanair establish a brand and persuade people who may have been cynical about low-cost operators to try the airline.

"We found that Ryanair doesn't conduct customer surveys, like many other airlines do; instead the management team rely on their intuition or feedback from their employees. They are always keen to try something new, which reflects the airline's entrepreneurial spirit," she said.

Ryanair believes that 60 per cent of its customers want a good price while 30 per cent rate convenience and punctual flights as high up on the list of desirables.

This belief is borne out in the latest industry figures, which show that in August Ryanair grew its passenger numbers to one million in one month for the first time in its 14-year history. Latest statistics show the airline's passenger traffic in August grew 35 per cent to 1.20 million people.