A new study by Podzinger finds that consumers will tolerate video ads while they are surfing online, provided the ads are short and relevant to the content they are viewing.

Consumers have shorter attention spans online and as a result will generally expect video ads to be shorter than the standard 30-second TV spot, ClickZ reports the study as concluding. Most study respondents said they wouldn't spend more than a minute watching a video online, therefore marketers should consider making their ads no longer than 15 seconds, and closer to the beginning rather than the end of the video.

Almost three-quarters of respondents viewed relevant search advertising positively, but the level of relevance that's acceptable differs for audio and video search: users expect more specific relevance from search text ads.

Still, advertisers are unsure whether they should advertise on popular online video sites such as YouTube and MySpace. "It's hard for advertisers to decide…because a large portion of what's on there is garbage, pornography, or it's illegal," said Alex Laats, CEO of PodZinger. "If they know how content is being used and how it's being classified, they can have confidence in the delivery of their brand message in that environment."

More study results are available on PodZinger's blog.