Nielsen: Facebook Remains The Top App Of 2015, But Messenger Was The Fastest-Growing
Facebook this year continued to hold the number one position as the top app installed on U.S. smartphones based on the average number of unique users, according to a new report out this week from Nielsen …
Context & Ripple Effects
Nielsen's 2015 ranking lands mid-way through Messenger's breakout year: back in September, ComScore already showed Messenger displacing YouTube as America's second most popular app once US smartphone penetration hit 77%, and Facebook held four of the ten slots on App Annie's all-time iOS downloads chart. The Nielsen data adds average monthly uniques to that picture, confirming the unbundled Messenger isn't cannibalizing the flagship — it's compounding it.
What makes the report more than an annual scorecard is its forward confirmation: Nielsen's own 2016 follow-up shows Messenger growing 28% YoY to 129M uniques, faster than Facebook itself at 14%, meaning the growth curve reported here was the start of a durable pattern rather than a one-year spike.
First-order effects
- Facebook ends 2015 holding both the #1 overall position and the fastest-growing property on US smartphones, giving its ad business verified cross-app reach data from an independent measurer.
Second-order effects
- Google faces pressure on the engagement side: with Nielsen crowning Messenger and ComScore already showing it ahead of YouTube as the #2 app, YouTube's long-held runner-up slot becomes contested turf.
- Measurement rivals like ComScore are pushed to match Nielsen's app-uniques methodology, since ad buyers now have two competing yardsticks for cross-app audiences.
Third-order effects
- If Messenger-class growth persists — as Nielsen's 2016 numbers indicate — messaging apps consolidate into the default social surface of the smartphone era, shifting where publishers and brands must maintain presence and how audience size gets measured (installed-app uniques rather than site visits).
The trend: Messaging apps are becoming the primary engagement layer on smartphones, with independent measurers like Nielsen and ComScore racing to quantify audiences that span multiple owned apps.