• by Gavin O'Malley  @mp_gavin, May 6, 2010

While ad networks and other collective buying channels continue to attract media buyers, the majority still prefer buying by the site, according to a new report from research firm Advertiser Perceptions, which was commissioned by ad network and technology provider Collective Media.

A full 52% of respondents indicated they would increase spending on content sites -- such as ESPN and WebMD -- this year.

What's more, nearly half -- 46% -- of respondents reported a site-centric focus, with spending increases limited to vertical content and video sites.

Overall, 34% of respondents indicated that they would increase online ad spending in 2010, with 35% of respondents indicating they would increase spending on ad networks. Large online spenders -- those spending $10 million or more -- were slightly more likely -- 40% -- to use ad networks, according to the study. Meanwhile, 46% of respondents indicated they would increase spending on video sites in 2010, while 67% of large spenders would increase spending on video sites. By contrast, just 23% of survey takers said they planned to increase spending on portals this year.

Between February 2009 and February 2010, Advertiser Perceptions says it conducted 420 online interviews with respondents involved in the online media industry "with decision-making involvement for advertising campaigns." The advertiser and agency sample -- across 16 categories -- was provided by Advertiser Perceptions, which offered a cash incentive to all participants.

Behind the continued strength of digital, Advertiser Perceptions found that advertisers are continuing to shift toward "more accountable, measurable results."

Going forward, a key challenge for digital brands is the proliferation of new media opportunities and competition among the major portals, ad networks, content sites, social media and video.

As the online advertising ecosystem continues to evolve, the reports point to an increased emphasis on audience knowledge and insights, and the use of brand-centric effectiveness measures. Indeed, the majority -- 53% -- of agencies surveyed believed that having more data providers integrated into the targeting system provides for more effective campaigns. Meanwhile, 20% of senior executives said it "helps significantly."