More than half of all ads on Meta’s Instagram ran in the service’s short-form video Reels product in 2025, up from 35% in 2024, according to data from market intelligence firm Sensor Tower.

In the U.S., Reels accounted for 46% of time spent on the Instagram app in 2025, up from 37% in 2024, according to the data that Sensor Towered showed CNBC. On the Facebook app, that figure reached 29% in 2025, up from in 2024.

The shift highlights the growing role Reels plays in Meta’s efforts to drive engagement and advertising revenue across its Instagram and Facebook services.

Vertical video continues to be a valuable artificial intelligence play for these social media platforms. Companies like as Meta, Google’s YouTube and TikTok rely on recommendation systems powered by AI that surface personalized videos designed to keep users engaged for longer periods of time.

The platforms’ value in AI tools comes from the ability to serve users relevant content, Neuberger Berman senior research analyst Dan Flax said.

“They’re surfacing content to the user, and as they get more signals based on what the user watches … that’s helped their recommendation engines get better and you’ve seen it in the Reels revenue number,” said Flax.

Advertisers have followed this trend, shifting their focus towards short-form video in the past year to reach more consumers on Reels.

“Legacy services are seeing ad volume shift away, with advertisers prioritizing more Reels to meet users where they are,” Abraham Yousef, a senior insights analyst at Sensor Tower told CNBC.

But the rise of Reels has presented monetization challenges for Meta, as short-form video typically generates less revenue than Instagram’s main feed. Meta CEO Mark Zuckerberg pointed out this trade-off during an earnings call in 2023 when Meta stopped paying creators directly for posting Reels.

“Currently, the monetization efficiency of Reels is much less than Feed,” Zuckerberg said at the time. “So the more that Reels grows, even though it adds engagement to the system overall, it takes some time away from Feed and we actually lose money.”

The data shows that while Reels viewership share goes up, so does all activity on the app. Instagram’s daily active users are up 2% since last year, led by increased usage of Reels, according to Sensor Tower.

Meta declined to comment.

Analysts say the growing share of viewership on Reels can still translate into higher overall advertising revenue for Meta.

“Even as you substitute some feed at a higher monetization rate than Reels, you still are growing, in totality, the amount of advertising Dollars that advertisers are spending with Meta,” Flax said.

Zuckerberg announced on an earnings call in October that Instagram and Facebook Reels had surpassed a $50 billion annual run rate. Analysts will be looking to see how that has grown when Meta reports fourth-quarter and full year results for 2025 on Jan. 28.

Last September, Meta announced that Instagram had amassed 3 billion monthly active users, a major milestone for the photo-sharing app, which was acquired in 2012 for $1 billion.

As Reels becomes a larger share of how users and advertisers interact with Meta’s apps, the focus shifts to whether the format can remain dominant amid competition from TikTok and YouTube, which offers a similar short-form video product called Shorts.

In December, Meta introduced an Instagram TV app that can be used on Amazon Fire TV streaming devices. The app lets users can watch Reels on their televisions.

“What Meta has done incredibly well with Reels is that they have gotten better and better with the recommendation engines,” said Flax. “I give Mark Zuckerberg and the Meta leadership a lot of credit for wrapping Reels effectively, and I frankly think it has a very strong outlook.”

While Meta’s Reels share continues to grow year-over-year, Sensor Tower’s data showed YouTube’s watch time for Shorts was flat last year.

Nonetheless, YouTube continues to outpace both Instagram and TikTok on mobile, with Sensor Tower estimating U.S. daily active users grew 3% in 2025. TikTok, however, still leads in time spent, with users averaging 81 minutes per day on the app, compared with 80 minutes on YouTube and 55 minutes on Instagram.

As that three-way race continues, algorithm-driven vertical video has become a central battleground for how social media companies attract users, sell advertising and sustain growth.

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