The top 50 agencies accounted for the bulk of the revenue – $7.84bn – which was down 3.1% year-on-year, but the top-line figures masked differing fortunes for the nine “basically large database companies” and the ad-hoc survey vendors, said Honomichl.

In total Nielsen, IMS, Arbitron, NPD Group, SymphonyIRI, JD Power, National Research Group, ComScore and Rentrak showed no revenue change from 2008, “and in this economy, flat is good,” said Honomichl.

“If you take the 41 top 50 companies that are basically survey/qualitative vendors, their revenues were down 7%,” he said.

Smaller agencies fared even worse. Outside of the top 50, the 153 member companies of the Council of American Survey Research Organisations who participate in the survey had an average of $5m in annual revenue and as a group their revenue was down 8.5%.

“The smaller and more ad-hoc a business is, the harder it was hit in this recession,” said Honomichl.

The full report, plus tables, is published in the current issue of the American Marketing Association’s Marketing News magazine and can be viewed online here (although access to the tables are restricted to members).

US industry growth in 2008 was 1.6%. Although 2009 was hard-going, the US performance compares favourably to the UK, where recent figures produced by the Market Research Society show revenue down 4.7% last year to £2.08bn.