Eyeblaster's report looked at thousands of brands and found that video ads outperform in relation to editorial content, specifically news, finance, music and sports, but lag in social environments. Over the three and a half years, the study found video impressions grew 60% faster than rich media impressions.

It all comes down to "dwell time" — the amount of time that people spend looking at a page online. Eyeblaster found that video ads generally boost "dwell rate" — the proportion of time spent clicking or lingering over an ad — by 20%. In areas that video ads perform well, they yield double the ROI of non-video rich media.

But that all changes in social, where users browse very quickly and tend not to linger. Ariel Geifman, research analyst at Eyeblaster, tells Econsultancy:

"People do spend ample time on social networks, but not as much on a single page.  Users may log in and out multiple times per day, or browse between pages more quickly.  As a result, the performance of video ads in these environments is inferior as compared to other environments."

In sectors like gaming, where users engage with the interface for longer periods, they see an ad for longer, but there are drawbacks. Gamers are less likely to actually click on an ad while playing, so gaming ads work better for branding purposes. Eyeblaster found that video ads perform best when next to static content that takes longer to consume. Says Geifman:

"Video works well in environments with more in-depth content, such as news, finance and email. In these environments, users spend ample time on the same webpage reading content (or in the email case also writing content). When users spend a long time on the same page, they are more inclined to engage with ads, and with video ads in particular. We’ve seen that video ads require users to spend more time on the page due to the time it takes for the ads to load, and play to their full duration. When users spend more time reading in-depth content, they engage with video ads more frequently, and ultimately, allow more videos to play to their full duration."

Video is a rapidly growing segment, with 161 million U.S. internet users watching online video during August of this year, according to comScore. And Nielsen registered that the number of video streams watched by U.S. viewers increased by 24.8% between September of 2008 and September 2009. The average time per viewer also increased by 24.8% over the same time period.

Which makes it likely that video will start performing better in social when users get more accustomed with the medium — and publishers adjust their inventory according to browsing habits.

"It's not about the mind-set, it's the browsing habits. That said, people don't browse [in social] as they do in news and finance, where they read an article and have more time to look at an ad," says Giefman. "Video is still a very much emerging medium, and this is a picture of video right now. People will continue find ways of engaging people in different environments."

Image: MaximumPC