Think you can easily spot an ad on social media?
You might want to think again.
New research shows that on platforms like Instagram, ads are far better at hiding in plain sight than most of us realize.
Many of them are designed to look and feel like the regular posts from friends or influencers we follow—and that makes them surprisingly hard to detect.
A team of scientists at the University of Twente wanted to understand how people actually experience ads while scrolling, not just what they think they notice.
“We scroll on autopilot, and that’s when ads slip through,” explained Maike Hübner, a Ph.D. candidate and lead author of the study published in Frontiers in Psychology.
“Some ads are even made to reflect the trends or products our friends are talking about. That makes them especially hard to resist.”
The researchers studied how long people looked at ads versus regular posts, what parts of the posts they focused on, and how they reacted once they realized something was an ad.
They recruited 152 regular Instagram users and showed each of them one of three fake Instagram feeds. Each feed contained 29 posts: 21 organic ones and 8 ads.
Participants were told to imagine the feed was their own and to scroll as they normally would.
Using eye-tracking software, the researchers measured “fixations”—how often someone’s gaze landed on a particular part of a post—and “dwell time,” or how long their eyes stayed there. Short dwell times suggested a quick glance, while longer ones indicated real attention.
After scrolling, participants were interviewed about what they noticed. While many spotted official ad labels when they were clearly visible, the eye-tracking data revealed that people often picked up on other cues first.
Calls to action, such as “shop now” buttons or sign-up links, were a common giveaway. Brand names, verification badges, and highly polished visuals also tipped people off, sometimes even before they noticed any official “sponsored” label.
However, not all ads were so easy to detect. Posts that blended in with the casual style of organic content—using less polished images or mimicking influencer posts—often went unnoticed. When participants didn’t spot the usual clues, these ads got just as much engagement as regular posts.
When people did recognize an ad, their behavior changed quickly. Many stopped engaging with it, and their dwell time dropped sharply. Still, some participants admitted they didn’t mind if a post turned out to be an ad, and that group, Hübner suggested, might be the most concerning. “When we stop noticing or caring that something is an ad, the boundary between persuasion and information becomes very thin,” she said.
The study suggests that transparency in advertising isn’t just about labeling posts as sponsored. It’s about understanding how people truly process ads during everyday scrolling—and rethinking how platforms design and regulate content so that users know when they’re being marketed to.
This research was done in a controlled lab setting with simulated feeds, and the researchers note that results could differ in real-world conditions, different cultures, or on other social media platforms. In fact, Hübner believes ads could be even harder to spot in someone’s personal feed, where the content is tailored to their interests and feels more familiar and trustworthy.
“Even in a neutral feed, people struggled to tell ads from regular content,” she said. “In your own feed, it’s likely even more difficult—because the ads are designed to feel like they belong there.”
