In the latest example of how online video advertising is becoming more precise, is experimenting with a range of ad formats, ad lengths, and the time intervals to deliver them to Web consumers. That's what Mark Marvel, senior director of video at told Andy last week. has worked closely with pharmaceutical advertiser Pfizer over the past 12 months to offer 60-second spots in exchange for watching six minutes of news videos commercial free, Marvel explained.

That's similar to a Hulu ad format that lets viewers opt in to watch a two-minute ad in exchange for no more ads during the rest of a 22-minute show, for instance. Web sites with premium video and TV shows, like and Hulu, are testing different ad formats because of the shift to more longer-form viewing online that's been documented by research firms like comScore.

Marvel said is also experimenting with the variety of ad formats it can serve up during different viewing time intervals. There could be any number of combinations, such as interactive ads, bugs under the player, or even keyword-based ads that might appear during a show, but would be delivered at reasonable "time-based intervals," he said.

Marvel will be a participant in tomorrow's Beet.TV Online Video Roundtable

Daisy Whitney, Senior Producer