A new report from the Interactive Advertising Bureau and PricewaterhouseCoopers indicates that online advertising spending declined by 5.3 percent in the first half of 2009.

Specifically, online ad spending during the first half of this year was 5.3 percent below that during the first half of 2008. Search ad spending, however, rose during the period – it grew by 47 percent compared with a growth rate of 44 percent over the same period last year. Altogether, search ad revenue was up from $5 billion to $5.15 billion.

In its report, ‘Internet Radio Makes Waves’, eMarketer says terrestrial radio will continue to struggle in 2009 as advertising expenditure drops by 18 percent from that in 2008, resulting in ad revenues of $14.5 billion. In fact, according to the Radio Advertising Bureau (RAB) the first quarter of 2009 was the industry’s worst quarter ever in terms of ad spending.

That doesn’t mean radio per se is doomed. Indeed, as terrestrial radio stations decline, Internet radio stations are benefiting from growing ad revenues year over year, making Internet radio one of the fastest-growing online media categories.

eMarketer expects that, worldwide, growth in social network advertising will be 9 percent in 2009, reaching $2.2 billion. This is down from eMarketer’s March 2009 forecast of 17 percent growth for the year.

eMarketer expects worldwide social network ad spending to grow substantially in 2010 though. The firm expects growth to be 18 percent in 2010, resulting in advertisers spending $2.6 billion on social networks across the globe.

Research by Borrell Associates indicates that local businesses are responsible for nearly 20 percent of all advertising spending on social networking sites.

Borrell estimates that local advertisers will account for approximately $641 million of the almost $3.3 billion spent on social network advertising in 2009.

Silicon Alley Insider has deemed 2009 to be the year the newspaper died. Well, if it didn’t die this year, it’s probably fair to say that 2009 was the year the newspaper went into free-fall.

In the United States, at least, the facts paint a pretty stark picture of the plight of newspapers. We’re just over half-way through the year and already:

Based on the Newspaper Association of America’s figures, 2008 saw advertising spending in newspapers drop by 16.6 percent across each of the national, retail, classified and online categories.

Classified advertising, which accounts for the largest proportion of newspapers’ ad revenue, dropped by 29.7 percent from $42.2 billion in 2007 to 34.7 billion in 2008.

Research by Borrell Associates predicts that by the end of 2013, local online advertising expenditure by small-to-medium (SMB) U.S. businesses will grow by almost 34 percent from 2008 levels.

Furthermore, companies involved in local online marketing will invest almost 70 percent of their online ad budgets on paid search and video.

As you might expect (given lies, damned lies and statistics), research firms are sending mixed messages about the state of search advertising expenditure.

On the one hand, eMarketer reports that Google and Yahoo have reported year-over-year increases in their search revenues for the quarter ended December 31, 2008 (Google by 17 percent and Yahoo by 18 percent).

Data by TNS Media Intelligence indicates that, overall, advertising expenditure declined 1.7 percent during the first nine months of 2008 compared to the same period in 2007.

Further, while ad spending on display ads increased 7 percent during this period, advertisers are increasing their display spend at a slower rate than they’ve done so in the last few years.

The declining growth rate in display spending may not, however, cause ad rates to decline by much, if at all. TNS Media Intelligence has found that the number of display ads has decreased, resulting in the price of ads holding steady.

Source: Douglas Quenqua, “TNS: Ad Buyers Hit the Brakes in Q3″, ClickZ, December 11, 2008

Despite indications that online advertising expenditure, including search engine advertising is either down or flattening, AdGooroo reports that first page advertising activity on all three major search engines was up sharply during the first two months of the fourth quarter of 2008.

Not only was first page spending up during this period, but the growth in first-page advertisers was substantially higher than that in the fourth quarter of 2007. Here are the growth percentages:

AdGooroo points out that while advertiser counts are higher on all three search engines, Google’s 55 percent increase is beyond what can be expected from seasonality alone. It attributes the remaining increase to Google expanding its ad coverage.

Meanwhile, AdGooroo estimates that Microsoft has increased its advertiser share from 11.5 percent in Q3 to about 15.8 percent in Q4 (a 37 percent increase). This brings Microsoft much closer to Yahoo in terms of being the preferred search engine channel for search engine marketers. Currently, Yahoo has a 22.1 percent share, while Google has an 80.3 percent share.

Source: AdGooroo, “AdGooroo Mid-Quarter Search Engine Update – Q408″, AdGooroo, December 4, 2008