Threads Social Proof
Turned people's existing Facebook connections into the reason to try, adopt, and come back to Threads.
Context
The Threads promo unit in Facebook Feed was generating impressions but not conversions. Shown inline as users scrolled, it blended into the feed without giving anyone a reason to stop. The core challenge: making a promo unit feel personally relevant at scale.
Problem
The unit needed a reason to stop the scroll. My hypothesis: people are more likely to try a new app when they see that their friends are already using it. Social proof, specifically showing recognizable friend faces, would create a personal connection that generic units couldn't achieve.
Two audiences, one mechanic
But "the user" wasn't one person. The same social proof mechanic had to serve two different audiences for two different reasons, so the flow had to branch depending on who was looking.
Acquisition · new usersGoals
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Design process
1 · Research & discovery
In partnership with UX Research, the team surfaced three critical behavioral patterns:
- Users didn't recognize Threads usernames (IG-style handles) as people they knew on Facebook. That's a cross-platform identity gap that undermined connection.
- There was low ambient awareness that close friends were already active on Threads. The missing piece wasn't interest; it was signal.
- Younger users spent less time scrolling Feed than older cohorts, so a Feed-only signal would have missed a meaningful slice of the audience.
2 · Identifying opportunities
Mapping the Facebook user journey, Feed stood out as the highest-intent touchpoint: people were already browsing content there, so a friend's face added credibility without interrupting the scroll. That's where I focused the exploration below. The same facepile logic later extended to the install flow and to notifications, but Feed is where the idea took shape.
3 · Design explorations
Before committing to a system, the Feed unit was where I could test fastest. Three versions went head-to-head: no social proof at all, a basic two-friend facepile, and an enhanced version showing three or more friends with bolder copy. The enhanced version drove 6x the click-through rate of the no-proof baseline, proof that more social context, not just presence, is what actually moved people.
Click-through rate by variant
Final designs
The winning combination, friend faces plus a reason to care, started here in Feed, the surface where I could test and iterate fastest. From there, the same pattern rolled out to the install flow and to notifications too.
Results
Impact & learnings
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What's next
Following the global rollout, the team is:
- Expanding social proof to Stories and Reels surfaces, extending the pattern to full-screen, higher-attention formats.
- Testing expanded targeting to reach additional user segments beyond the initial cohorts.
- Exploring richer social signals, like friend activity and shared interests, beyond simple platform presence.
The bigger lesson: a well-designed social signal can drive real cross-app growth without costing user trust or platform quality.