The top 50 agencies accounted for just over $8bn in revenue. Nielsen led the pack with $2.2bn in domestic sales, followed by the recently-merged TNS and Kantar Group with combined revenue of $918m.

Familiar names made up the bulk of the table, however there were five new entries. Highest-placed was online community builder Communispace, coming in at 29 and with year-on-year growth of 27% to $29m. Other newcomers were Iconoculture ( 40 ), CMI ( 45 ), Chadwick Martin Bailey ( 47 ) and Roger Green & Associates ( 50 ).

Seventeen firms saw year-on-year declines in revenue, 11 of which featured in the first-half of the table.

The top 10 agencies by US revenue were:

1. Nielsen – $2,231m, down 0.4%
2. Kantar Group – $918m, down 5.1%
3. IMS Health – $842m, up 3.1%
4. Westat – $469m, up 0.5%
5. IRI – $454m, up 3%
6. Arbitron – $364.4m, up 9.4%
7. GfK USA – $313m, down 2.2%
8. Ipsos – $307.6m, up 4.2%
9. Synovate – $245m, down 2.8%
10. Maritz Research – $197m, up 5.3%

NB: Rate of growth year to year excludes revenue gains and losses from acquisitions or divestitures.

The Honomichl Top 50 is published by Marketing News, a magazine of the American Marketing Association. Visit www.marketingpower.com for more information.