The company that provides fine-tuned scores rating 600 million YouTube and Facebook videos for advertisers will soon expand its horizons beyond those two key platforms.

OpenSlate’s Slate Score measures content quality, whilst the company also charts videos’ subject matter expertise and brand safety.

In this video interview with Beet.TV, CEO Mike Henry says the company also plans to rate other videos offered by premium publishers.

“We started with YouTube, we expanded into Facebook earlier this year,” says Henry. “We’ll be announcing more platforms soon.

“We’re certainly interested in other platforms where people are watching video. Once you get beyond the (big) platforms, we’re interested in all ad-supported video.”

Henry says the interest in tracking new video destinations is “being driven by our clients”.

“Big brands like Proctor & Gamble and Unilever want to understand where they should be and where they shouldn’t be on those platforms,” he says. “They want to understand the differences between something they might buy on YouTube or Facebook and something they might buy on CBS or Hulu. So over time, our vision is ubiquity and a consistent set of metrics for all online video.”

OpenSlate provides data about the content, subject matter and suitability of more than 600 million YouTube and Facebook videos for advertisers to determine whether the inventory is a good fit for their brand.

It is one of a growing plethora of “brand safety” tools aiming to give ad buyers more control.

Last month, Nielsen invested to acquire a minority stake in OpenSlate. – a move Henry says “adds some power and promise to that vision” The deal puts the valuation of OpenSlate at $100 million, the Wall Street Journal reported based on its sources.