Facebook Inc. (FB.O) lost ground to Google in January as users spent more time on YouTube and other Alphabet Inc. (GOOGL.O) properties, according to a report.

Brian Wieser, a Pivotal Research analyst who reviewed Nielsen digital consumption data, said that while the amount of content people consume doesn’t necessarily relate directly to how the sites can make money, it does indirectly impact advertiser sentiment toward the platforms. Nielsen published its Digital Content Ratings on Tuesday.

Facebook depends on people coming back frequently so it can collect data and use it to target ads at them. The company said in the fourth quarter that people were spending less time on the site after Facebook began shifting users’ news feeds back toward posts from friends and family and away from businesses and media outlets. But if the trend continues, investors could take it as a sign that users are losing interest in Facebook.

Analysts are closely watching the social network’s user engagement amid revelations last month that the private data of millions of people was scooped up by the political consulting firm Cambridge Analytica. The resulting furor sparked a #deleteFacebook movement and forced Chief Executive Officer Mark Zuckerberg to testify to Congress.

Facebook shares were up 1 per cent to US$166.73 at 9:35 a.m. in New York, after closing up 4.5 per cent Tuesday.

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Google properties, including YouTube, and Waze, combined to account for 27.4 per cent of all time spent on digital media, Wieser notes. YouTube accounts for half of all Google activity and continues to draw consumption well in excess of 20 per cent year-over-year every month. Other Google properties expanded by 33 percent.

Facebook appears to be going in the other direction, Wieser said. Facebook’s main site lost 5 per cent in time spent, despite a 4 per cent increase in the number of users. That amounts to an 8 per cent decline per person, he said. Instagram, a Facebook property, did much better with a 7 per cent increase in time per user.

Overall, including WhatsApp and Instagram, Facebook had about 16 per cent of the digital consumption market. That’s “significantly below” Wieser’s forecast for Facebook’s share of digital ad revenue, which he estimates at about 23 percent in the U.S. this year.