The power of YouTube's ad-targeting abilities -- enabled by both its own user data and outside data it can get with Google's help -- have also helped its cause. So have its investments in building quality measurement tools that help companies gauge the impact of a video ad on things like awareness of a product and attitudes towards the brand that's selling it.
How does a video streaming service with one billion active users per month and $4 billion in revenue not turn a profit? Ask YouTube, which couldn't break free from breaking even in 2014, according to a new report. Sources tell the Wall Street Journal that Google's video unit posted $4 billion in revenue last year, up from $3 billion in 2013, and that while the service accounted for 6 percent of Google's overall sales, it contributed nothing to earnings.