The Online Publishers Association regularly looks at online advertising effectiveness—and probably not too surprisingly, their members once again see the best rates of ad effectiveness in several measures.

The study examines ads place on OPA member sites (content sites including major news sites, etc.), Dynamic Logic’s MarketNorms industry benchmark, portals, and ad networks, and analyzes their effectiveness at aiding brand awareness, increasing awareness of their ads online, increasing awareness of their brand message, augmenting brand favorability and lifting purchase intent. OPA member sites saw the best rates in all these areas:

These results are fairly similar to the last time they tabulated them, August 2009. Notably, every delta measured has decreased since the last study reporting.

The OPA also broke the results out by demographics. Notably, the purchase intent for ad networks was strongly negative (and about where it was in August):

I suppose the good news for ad networks is that they’re not getting any worse!

The OPA’s bottom line is that content sites perform better for advertising—not a huge surprise, really, especially if the ads have been carefully crafted and tailored to the site. Ad networks seldom have that option, going for the big net theory instead.

The full study is available as a 39-page PDF.

What do you think? Are these results surprising? Do you see a difference between advertising on ad networks and content sites?