A Sussex mathematician has developed an equation to take the guesswork out of advertising online. 

When someone enters a phrase - 'bank accounts', for example - into a search engine, such as Google, a number of adverts or sponsored links appear alongside the search results. 

The research confirmed that an advert's position within these results affects how many people click on it, with those higher up achieving a better 'click-through rate'. 

Advertisers bid for these spaces by selecting keywords related to their product or service - for example, 'bank', 'account', 'overdraft' - which, when entered by a user, make the advert appear. 

Under the pay per click (PPC) system, advertisers are charged each time somebody clicks on their advert and have to pay more to appear nearer the top of the page. 

Until now, however, companies had to rely on time-consuming and costly trial and error to work out whether a premium spot would generate enough extra clicks to make it worth paying the extra money. 

Thanks to Dr Istvan Kiss, Senior Lecturer in Mathematics, they can now make these predictions using a mathematical formula, saving them time and money and avoiding costly mistakes. 

The project - a collaboration with Brighton-based digital marketing firm DC Storm - is an excellent example of academic expertise being used to solve real-life problems, says Professor Bob Allison, Pro-Vice-Chancellor (Research). He says: "Working with a local company, this project strengthens an already excellent working relationship with Brighton's thriving digital media community. 

"It's great to see a Sussex mathematician applying his skills and knowledge to solve a specific problem in the business world. 

"It shows how Sussex research skills and experience can aid business growth and innovation. 

"We can and must continue to engage and reach out beyond the campus to carry out research in this way and draw in new funding from beyond the research councils." 

Seth Richardson, CEO of DC Storm, says: "The findings will help advertisers get to their most efficient positions quicker and save them money in the long term too." 

DC Storm was able to fund Dr Kiss' research with an Innovation Voucher worth £4,000 from the South East England Development Agency (SEEDA). 

The Vouchers are designed to enable small businesses in the South East develop technology, start research, and access equipment and expertise or technical consultancy from universities.