The series of Sainsbury's TV adverts featuring the chef Jamie Oliver have been heralded this week as 'a test-bed for scientific measurements of the effectiveness' of expensive advertising campaigns.

In the recent past, advertising agencies relied on their gut instinct to deduce the effectiveness of a campaign. Now, sophisticated analysis by specialist consultants allows agencies to see just where they have been going wrong – or right.

In a report, entitled 'Sainsbury's: A Recipe for Success', agency Abbot Mead Vickers explains that the £41m spent by the supermarket on the Jamie Oliver campaign generated in excess of £1.12bn in extra sales during it's two-year run. This equates to around £5 profit for each £1 spent on the Sainsbury's campaign, and led to an increase in shareholder value of £1.76bn.

Sainsbury's joint managing director, Sara Weller, told the Guardian: 'Ads sell nothing. Without the improvement in service, ranges and store development, we would have nothing to advertise. Within the business they know that Jamie communicates that.' Bridget Angear, who co-wrote the report, says the arrival of Sir Peter Davis was crucial to the implementation of the campaign. 'The [report] never tried to claim that the advertising was responsible for Sainsbury's turnaround,' she said. 'Sir Peter Davis arrived in March 2000 and three months later commissioned the Jamie Oliver campaign. He's made many good decisions, one of which was hiring Jamie.' During the past two years of the campaign's TV run, success stories have included sales of ingredients for a prawn curry featured in one advert rising to the equivalent of 310,000 recipes; and a 3,000 per cent increase in sales of goose fat following an ad last Christmas.