At the International Consumer Electronics Show (CES), YouTube’s chief product officer, Neal Mohan, announced that a staggering majority of watch time on the platform — to the tune of 70% — is driven not by user search, but by the company’s own masterful recommendations, which are powered by artificial intelligence and machine learning.

And the fact that YouTube is so good at suggesting videos — which is no small feat given that 400 hours of content are uploaded to the site every minute — has resulted in longer watch times, said Mohan (pictured above). Today, the average viewing session on a mobile device lasts more than an hour.

“We focused a lot in the last several years on machine learning and artificial intelligence to learn what our users like and make,” Mohan said, per CNET, at the Las Vegas tech conference. “Our job is to give a steady stream — almost a synthetic or personalized channel.”