Tubular Labs, a four-year-old company that measures cross-platform Internet video viewing and engagement, has raised $10 million in financing led by venture-capital firm Marker to help fuel its push against comScore and Nielsen, two bigger rivals in the audience-measurement business.

The round brings the company’s total funding to date to $31 million. Previous investors include FirstMark Capital, Canaan Partners, Lerer Hippeau Ventures and SV Angel.

Tubular Labs tracks billions of monthly video views across 30 platforms, including YouTube and Facebook. The company’s customers include Viacom, Warner Bros., Scripps Networks Interactive, Activision Blizzard, AwesomenessTV, Disney’s Maker Studios and Fullscreen.

“Our goal since the beginning has been to help brands and publishers grow their online audiences,” Rob Gabel, CEO and founder of Tubular Labs, said in announcing the funding. “We’re thrilled to partner with Marker and will use this new funding to expand our offerings, enabling publishers to effectively prospect, pitch and report on branded content.”

Tubular Labs this week launched Media Property Rankings, which shows major media companies’ monthly views across all online video platforms ranked against their competitors. According to the company, BuzzFeed topped the list with 4.24 billion views in April 2016 across its 94 online video properties, followed by Time Warner with 2.17 billion, Disney with 2.02 billion, Comcast with 1.97 billion and the LADBible Group with 1.69 billion.

The Tubular Video Ratings, which debuted in April, provides benchmarks for reach and engagement of videos, creators, brands and categories. Tubular’s Engagement Rating 30 (ER3) metric measures a video or publisher’s engagement rate compared against all content over a 30-day period.

“Tubular is a pioneer and the clear market leader in a rapidly growing, increasingly diverse and critical online video industry,” said Rick Scanlon, co-founder and partner at Marker, who claimed the company is “the standard in cross-platform video intelligence.”