NEW YORK (AdAge.com) -- Larger ad formats might be in vogue right now, but when it comes to online display advertising, bigger is not always better. Ad effectiveness depends less on size than it does on shape and placement, according to Dynamic Logic.
The ad-effectiveness measurement firm crunched results from 4,800 campaigns and found the best-performing ad unit, in terms of metrics such as brand awareness, recall and purchase intent, was the humble 180-pixel-by-150-pixel rectangle ad.
"It's generally thought that bigger is better when it comes to ad sizes," said Ken Mallon, senior VP-custom solutions at Dynamic Logic. "But the study is saying 'We're not sure.'"
The findings come at a time when web publishers are busy experimenting to see what kinds of ads work best. Last spring, the Interactive Advertising Bureau endorsed some larger ad sizes, and a few months ago Online Publisher Association member sites such as ESPN.com, NYTimes.com and WSJ.com started running larger ads as part of a push by the OPA to offer something beyond standard ad sizes. MySpace began offering larger ads on several of its entry pages a year ago. And last spring YouTube kicked off a larger "masthead" ad on its home page.
Mr. Mallon said it's not yet clear the effect these giant ad sizes will have, because Dynamic Logic hasn't studied enough of them. "We may learn things about larger ad formats, maybe super-large ad formats work really well," he said. "But among the limited range, it looks like where they're located on the page and their shape is more important than size."
Ads that surround content -- well-worn skyscraper and leaderboard units -- are the least effective, as people have developed "banner blindness," he said.
"It's like going into an art gallery -- if I find you later and ask what color the frame on such-and-such a painting was, you'll have no clue because you're trained to block out the frame. But you could probably answer questions about the paintings," he said.
By contrast, rectangular ads tend to be closer to and, in some cases, interrupt the content -- meaning that when you absorb the content, your eye naturally has to roll over the ad.
Don't forget the creative
Of course, there are also ads that can prove annoying to users and the No. 1 factor of ad effectiveness, according to Dynamic Logic, is creative.
"In the digital world, lots of time is spent optimizing targeting and campaign frequency, but the most important factor is starting with a good ad," said Mr. Mallon. "Just about any size will work better than a bad ad that's huge."
Perhaps not surprisingly, the firm has found that ads with poor creative can have a negative effect on people's opinions about a brand. Ads should never cover the content a user is trying to find; should not be so busy that they're annoying; and marketers should rethink their use of simple Flash-based -- the least effective of all the display formats measured. Indeed, several of those lessons are reinforced in a recent Harris Interactive poll, which found ads that cover content and don't have a "skip" or "close" button to be the most annoying formats.
In some cases, even good creative can have ill effects if it's done for the wrong brand. Mr. Mallon cites the example of a financial-services marketer that started running ads with a Flash-based game in them.
"It was a brand known as trustworthy and maybe a bit stodgy but in a good way," he recounted. "But someone on the team had been to a conference or something and saw gaming ads generate lots of engagement. So we did some research, particularly around trustworthiness, and found increased ad interaction was negatively related to the brand's trustworthiness."
A few tips from Dynamic Logic for making your ads effective:
Simple Flash is overused. Better choices are rich media with video or, if you're on a budget, standard GIF/JPEG ads. For every branding goal Dynamic Logic studied, simple Flash performed the weakest format.
Try to avoid ads that border content. Those are the most easily ignored.
Publishers should consider mixing up ad placement from page to page. By placing the same ad formats in the same place on every page, consumers become trained to avoid the ads. Think about what other content could run along the frames to help draw people's attention.
Not all attention is positive. Avoid flashing, blinking or just generally annoying ads. Not only do these not help a brand, they can actually have an adverse effect on a consumer's opinion of a brand.