With users consuming more online video than ever, marketers are set to spend more than $1 billion on online video advertising in 2010. We watched nearly 50 hours of video on 87 Web sites to learn more about how publishers and marketers are deploying in-video advertising — and found that 85% of US Web sites now accept in-stream video ads. However, not all in-stream ad inventory is equal. Marketers must consider not just the quality of a site's content but also whether the site offers companion ads and limits ad clutter. Marketers should also use multiple short creative executions and employ video sponsorships to cut through clutter.