Advertising on quality, original content sites is more effective than ads elsewhere on the Web, a new report released today by the Online Publishers Association has found.

According to the report, "Improving Ad Performance Online," ads on OPA sites were consistently more effective than portals, ad networks and the Web in terms of raising awareness, creating message association, generating brand favourability and driving purchase intent.

"Ad network performance has declined to a point where they provide no significant increase in purchase intent to advertisers. As a result of this insignificance, the average brand campaign may not achieve greater brand lift by advertising on an ad network," Pam Horan, president of the OPA, stated in a press release.

Using data from independent marketing database Dynamic Logic's MarketNorms, the study concluded that ad networks "provide advertisers with the smallest change across ad effectiveness metrics."

Minonline pointed out that the study continues to "jab at the large aggregators of remnant and small site inventory," after "a fight with ad networks that the OPA started last year with similar research findings."

The study also found that larger ad units, such as leaderboards and wide skyscrapers, as well as rich media and video all appear to benefit most from being in a branded media context.

The study's results give established content publishers some backing as they compete for advertising, iMedia Connection commented. "It's the second round of good news for content sites this month, after a separate study revealed that marketers plan to spend more on content than on ad networks."