Research shows that this basic ad unit is still the most accepted by consumers.

The final findings from Dynamic Logic's AdReaction research show that consumers prefer Web ads that are in or around content over those that cover up content or interrupt viewing.

Dynamic Logic asked for consumer reaction to the major online ad formats. The top four most popular (or least unpopular) Web ad formats are:

1) Banners
2) Skyscrapers
3) Pop-in Between Ads/Interstitials
4) Ads with Audio

The research indicates that consumers prefer the least intrusive ad formats to more intrusive ones. This includes more tolerance for ads that pop in between Web pages (Interstitials) than for pop-ups, which are at the bottom of the list.

"It may be that consumers are more willing to tolerate advertisements when they are perceived to be around or in between content as opposed to feeling that the content is being blocked by the ads," says the Dynamic Logic study. "It is a subtle, but perhaps significant perceptual difference that impacts consumers’ acceptance of the formats."

However, the fact that pop-unders are next to pop-ups at the bottom of the consumer preference list suggests that frequency is also a factor of consumer irritation. Since a pop-under does not block content, it does not seem as “intrusive” as a pop-up. But pop-unders tend to spawn many layers, and consumers are often forced to close multiple ads in a row. This would suggest that with better frequency controls, perhaps pop-unders and pop-ups could gain greater acceptance if used sparingly.

Indeed, other findings from the study indicate that viewers will accept up to two pop-ups per hour in exchange for free content.

What is also worth noting is that ads with video and audio, while still relatively new in Web advertising, are roughly in the middle of the pack. Dynamic Logic suggests that improvements in technology have made video-like ads more possible and advertisers are starting to employ TV-like ads online.

Yet there has been a fair amount of controversy within the industry regarding ads with audio, specifically over the concern that they have the potential to bring attention to people surfing the Web at work. Some publishers require that audio is defaulted off with an opt-on feature. Dynamic Logic says this type of Web advertising is gaining interest from both the advertiser side, and to some degree, from the consumer side. It may be, as suggested in other AdReaction research analysis, that TV-like Web ads bring entertainment, humor and drama value to Web advertising, which increases consumers’ interests.