YouTube unveiled its long-awaited and long-promised advertising platform, InVideo ads. The system places semi-transparent ad "overlays" at the bottom of its video player, which will disappear after 10 seconds if users don't click through to see more.

Those who select the ads will either follow a link to a new Web site or launch a new video player that will run the video ad. Advertisers can choose which videos will carry their ads, based on such target criteria as age, gender, location, and genre of video.

The company will charge on an impression basis, as well as provide click-through data. Launch partners include BMW and New Line Cinema.

Music videos, which represent a substantial portion of YouTube video streams, are considered ideal for the type of targeting advertising partners want to achieve. In most cases, they have an easily identifiable fan base that makes it much easier to guess the age and gender of the person likely watching it.

Exactly how YouTube will share this advertising revenue with content partners, however, was not addressed. A key agreement between YouTube and the major record labels is that the video-sharing service will identify when videos containing copyrighted music is aired, and subsequently share a portion of the advertising shown from that video with the content owner.