Google’s grand plan for YouTube is set to take a step forward today with the launch of in-video ads for a small group of the site’s clients.

The move, coming almost a year after Google’s $1.65bn purchase of the video sharing site, will see the web giant going out on a limb in its choice of format in a bid not to annoy the site’s 130m viewers.

Google has been testing the water with several ad types on YouTube over recent months, and has opted for animated overlays, rather than the pre-roll format that has been adopted much more widely by other video content providers.

The ads will appear in the bottom 20% of the screen 15 seconds after a viewer starts watching a clip, offering them the option to see a commercial while the video is paused. If the viewer doesn’t click on the ad, it disappears within 10 seconds.

Google said a select group of brands would be participating in the programme, and that it would run the ads with around 1,000 content providers. YouTube product manager Shiva Rajaraman told Reuters:

“We’re working with select partners … (including) people who are original content creators who have bubbled up and become popular. What we’re not doing is throwing this randomly across video on our site.”

Google has previously expressed fears that pre-roll ads could damage the user experience on YouTube, and says results of the in-video trials have been promising.

It says a survey of viewers found 73% said they didn’t mind the ads as long as the site’s content remained free, while 67% said the ads did not interfere with their experience. Still, that’s only two in three.

Update: The inital reaction of users has also been decidedly mixed.

According to this article in the San Francisco Chronicle, New Line Cinema was involved in the trials and found between 1.5% and 2% of the audience clicked on its ads.

eMarketer recently predicted that $775m would be spent on video advertising this year, up 89% from last year, and the market will have grown to $4.3bn by 2011.

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