• by Erik Sass  @eriksass1, February 22, 2011

Total radio advertising revenue rose 6% from $16.3 billion in 2009 to $17.3 billion in 2010, according to the latest figures from the Radio Advertising Bureau.

This relatively strong performance decisively reversed the downward trend of previous years, and included consecutive quarterly increases of 6% in the first quarter, 6% in the second, 5% in the third, and 7% in the fourth, when total revenues rose to just under $4.6 billion. p> Calling the fourth-quarter results "the best comparative figures we've seen in over a decade," RAB President and CEO Jeff Haley attributed the growth to big increases in key categories, including automotive, where spot spending jumped 22% in both the fourth quarter and full-year results.

The other top categories included communications and cellular, restaurants, TV networks and cable providers and financial services.

In terms of specific companies, the biggest advertisers in 2010 included AT&T, Verizon Wireless, McDonald's, Comcast Cable, Safeway, GEICO, JPMorgan Chase, Toyota Dealer Association, Walmart and Chrysler.

Total political spending came to $105.2 million, driven by the hotly contested midterm elections in November. (Forty-nine percent of all political spending occurred in the fourth quarter.)

As far as ad formats, digital advertising led the way with a 24% increase for the full year to $616 million, while spot edged up 6% to just under $14.2 billion, network increased 3% to $1.1 billion, and off-air grew 3% to just under $1.4 billion.

The strong digital growth is encouraging, but it represents just a small fraction (3.6%) of total radio ad revenues. The medium has a long way to go to make up lost ground: 2010's total of $17.3 billion is still down 20.3% from its peak of about $21.7 billion in 2006.