• by Gavin O'Malley  @mp_gavin, June 1, 2009

Over the next six months, a majority of senior marketing executives -- 53% -- plan to spend less on ad networks, according to the results of an "Ad Effectiveness Survey" released by Forbes on Monday.

During February and March, "respondents were by far the least happy with ad networks, with half saying that the results did not meet expectations," according to the survey of over 100 senior level executives.

"Ad network spending is all about demand fulfillment while direct-to-publisher display is much aligned with the traditional advertising goals of demand creation," said Forbes.com President and CEO Jim Spanfeller. "It is interesting to see the shift of dollars toward demand creation as we see signs of life in the economy."

Viral marketing and search engine optimization, meanwhile, are expected to see the biggest increases in spending in the coming months, according to Forbes, while behavioral targeting spending is expected to remain steady.

Indeed, among $1 million digital spenders, 54% expected to spend more on viral marketing, while 50% expected to spend more on SEO.

With regard to behavioral targeting, the greatest concern among respondents was its effectiveness, followed by fear of customer backlash.

Among the pool of senior marketing execs, the tools seen as most effective for generating conversions were SEO -- 48% -- email, and e-newsletter marketing -- 46% -- and pay-per-click/search marketing -- 32%.

Overall, respondents reported their appreciation for the halo effect that a Web site or publication can have on their brand, while 43% said that sponsoring a Web site, page or digital publication is the most effective digital tool when it comes to affecting brand perceptions.

Noted Spanfeller: "It's amazing that less than one-third of marketers are using brand perception metrics, despite the fact that the digital world makes brand perception research readily available and measurable."

A full 87% of respondents reported measuring results of their digital campaigns in some way, the most popular being benchmarking against goals set prior to the campaign.

The success of digital marketing appears to be measured by physical action, with impact to the bottom line being far and away the most important factor in determining success.