LOS ANGELES — The number of online video ads viewed in November was 5.4 billion, making ads 15 percent of all videos viewed, up 25 percent since June when they accounted for 12 percent according to data provided to Beet.TV from comScore.

While many of those ads were streamed by big publishers including Microsoft, AOL and Google, many have been serviced by video ad networks such as Tremor Media, Adap.tv, Brightroll, YuMe, BBE and several others.

Tremor was the biggest player, serving some 477 million ads in November, comScore reports.

Video Ad Networks: Big but Not Well Known

Despite the influence of these ad networks, an industry survey of agencies and marketers finds awareness of the video ad networks is "quite" low, says Andy Tu, VP of marketing for Break Media

Started as a Web video producer/distributor of male humor shows, Los Angeles-based Break has become a major video ad network with a growing staff and offices in several major media markets.

We spoke with Tu from his Los Angeles office via SkypeVideo.

Andy Plesser