In Ancient Greece, if you wanted to know what the fates had in store it meant a long trip up to Delphi and a nervous few minutes with the Oracle - a stoned priestess - and a bevy of clerks making sense of it all.

As the voice of the people has replaced Apollo's in deciding success in commerce and politics, we now have the mass hysteria that makes people buy Colgate instead of Pearl Drops or elect one slick public school boy over another. And in place of the Delphic priests we have market researchers to make sense of it all.

Market research is a billion-pound industry informing all levels of economic, social, and political decision-making, deciding what policies the Government takes up and how new products are developed.

Graduates should expect to start on £18,000 to £24,000 a year, with salaries after a few years averaging from £28,000 to £35,000, and top dogs earning up to £80,000 with sometimes generous benefits.

Although the influence of focus groups is most notorious in politics, most market researchers work, appropriately enough, in the marketplace, figuring out what people want and why.

Quantitative researchers work out whether, in fact, nine out of 10 cats do prefer Whiskas and what percentage of us are tempted to vote Tory. That does not mean you will be the one stuck outside Tesco on a wet Sunday afternoon asking the questions. Instead, you will be designing polls, collating the information and presenting it to clients.

So an understanding of sociology - knowing who to ask, psychology - knowing what to ask, and maths - making sense of the answers, is more important than a clipboard and a cheery manner.

Tim Williams has spent his career solving these puzzles. Now a director of the market research agency Blue Chip Research and Consultancy, Williams, 60, left university, like many market researchers, with a BA in sociology and psychology before joining a leading agency, Gallup, as a graduate trainee.

He says that quantitative research is more than just number crunching. "There's a lot of variety and there's a lot of creativity involved," he says.

"You're trying to understand what the opportunities are for clients in different markets. Your client is competing with other companies with the same data. Can you be creative in spotting opportunities?"

If your interest is in understanding individuals rather than the market, qualitative research may be more your bag. Once quantitative researchers have found out how popular a brand or policy is, qualitative researchers move in to find out why.

"You've got to be interested in people, what makes them tick," says Anjul Sharma. "You've got to be an interpreter, interpreting how they talk to you."

Sharma, 36, is a qualitative specialist and director of Synovate, a market-research agency and, like Williams, a sociology graduate. While Williams's work focuses around polls and questionnaires, Sharma spends much of her days attending group discussions.

"It's not just about what they tell you, it's what they do and feel," she says. "What's underneath what they're saying? Are they saying what they mean - or do they mean something else?"

Whether doing political or commercial research she says it is the surprises that market research constantly throws up that makes it most valuable as a career. "It's taught me an awful lot about the way people are," she says. "There are so many different people out there. You just think, how interesting that they think like this."

While most market researchers, like Williams and Sharma, work for agencies on a variety of different projects for different companies, some researchers work for one company, commissioning research and organising internal research.

Since graduating with a BA in business and marketing, Robin Birn, 52, has worked across the industry. He says that working directly for a company, rather than for an agency, gives you more scope to see the results of your research implemented.

"The important difference is that you're not in a mechanical process," says Birn, now head of consultation and research at the Institute of Chartered Accountants in England and Wales. "You get involved with the strategic planning of the business. In an agency you don't get to see the broader picture."

But it is the methodology of market research, a passion since university, that really enthuses Birn.

"It's not just about testing out ideas and assumptions, but learning things you didn't know already," he says. "If you research well, you'll always find something new."

For further information on careers in market research visit the Market Research Society website at