Music video streaming service Vevo has a huge audience, and now has some third-party data to prove it: Videos from the major-label owned streaming service were watched by 97 million Americans, or 25 percent of the U.S. population,  during the month of October, according to new data from comScore.

58 percent of that audience only accessed Vevo via phone or tablet. That’s significant, because ComScore only used to measure viewing data from desktop PCs.

“Very quickly our industry will have to reconsider the notion that mobile devices are a second screen,” said Vevo VP of Research Andrea Zapata in a statement. “These devices are the first and only screens used for a majority of our audience.”

But the data, which was released by Vevo Tuesday, also points to a lingering conflict with Google, a company that itself owns 10 percent of Vevo. The music video service has long been one of the biggest suppliers of major label content to YouTube, and most of Vevo’s traffic has been generated on YouTube.

Neither side has ever described this co-dependent relationship in concrete numbers, up until now: 43 percent of YouTube’s audience in the U.S. and the U.K. watched Vevo content in October, according to the comScore data released by Vevo.

Vevo has explored ways to bring more of that traffic to its own owned and operated properties. The service has relaunched its website and apps last year, and recently also began to experiment with windowing. In December, Vevo released Alessia Cara’s latest music video exclusively on its website, and only uploaded it to YouTube 48 hours later.