From an audience perspective, the ability to embed videos on other sites is what expands their viewership and makes them go viral. But from an advertising perspective, most of that video is the Web equivalent of dead air. "Nobody sells embedded video because nobody knows where it is going," says Magnify.net CEO Steve Rosenbaum. He has a partial fix for that, a new video advertising product he calls Elastic Inventory. Magnify offers a video aggregation platform that powers the video sections of mid-sized Web publishers such as New York Magazine , Bicycling , and The Week . Magnify lets these publishers upload their own video and mix that with video from more than 20 video sites across the Web such as YouTube, Metacafe , and Dailymotion . The problem is that those publishers can't run any pre-roll ads against those "curated" videos. But Magnify is starting to broker deals with the large video-sharing sites, starting with Metacafe, to allow publishers who use Magnify to insert their own pre-roll ads in the embedded videos.