Tremor Video, the biggest independent video ad network, has released a pre-roll unit which can expand to cover a majority  of the screen when activated by a viewer.

Its first implementation of the new unit is for the DreamWorks “Real Steel” motion picture.

Pricing is based on Cost Pre Engagment (CPE) so advertisers pay for impressions when viewers engage with the units, while Tremor Video’s ad-serving technology ensures the ads are delivered only to the viewers most likely to engage with the creative across the Tremor Video network, the company says.

Pricing on a cost-per-engagement basis has been a major focus of Tremor. In a recent Beet.TV Leadership, Tremor's Chief Media Officer Jason Krebs addressed the importance of engagement as the standard for pricing the emerging medium.

We have republished that video today.

Andy Plesser