Nielsen's 2016 top apps by monthly uniques: Facebook, up 14% YoY to 146M; Messenger, up 28% to 129M; and YouTube, up 20% to 113M; Amazon hits #10, up 43% to 65M
Context & Ripple Effects
This is the second year running that Nielsen has crowned Facebook the top US app, but the more interesting movement is beneath it: Messenger's fastest-growing-app momentum from 2015 carried through with another 28% jump to 129M uniques, confirming the split-off messaging strategy worked. The other notable entrant is Amazon, whose 43% surge to 65M uniques put it in the top ten for the first time in this ranking.
The measurement context matters too: back in September 2015, ComScore already showed Messenger displacing YouTube as the second most popular app as smartphone penetration hit 77% — so Nielsen's 2016 numbers read as confirmation that the top of the chart had settled into a Facebook-family-plus-Google pattern.
First-order effects
- Facebook now owns both of the top two slots by monthly uniques — 146M for the main app and 129M for Messenger — giving its ad business two distinct reach surfaces rather than one.
- Amazon's 43% growth to 65M uniques makes the shopping app a top-ten property, putting retail rivals' mobile apps in the position of chasing a storefront that consumers open habitually.
Second-order effects
- Advertisers get a cleaner story for splitting budgets between Facebook's social feed and YouTube's video inventory, since both now clear 100M+ monthly uniques — pressure that lands on mid-tier apps competing for the same brand dollars.
- Retailers without a comparably sticky app face a widening engagement gap against Amazon just as mobile becomes the default shopping surface implied by these reach numbers.
Third-order effects
- If the pattern holds, mobile attention consolidates around a handful of platform families — a trajectory the later Comscore data makes explicit, with Google's share of the top 15 US apps climbing from 33% to 46% between 2015 and 2021 while Facebook held flat at 20% (Comscore's 2021 tally).
- Third-party measurement firms like Nielsen and ComScore become the de facto arbiters of ad-platform reach claims, since rankings like this are what media buyers use to allocate spend across the winners.
The trend: US mobile usage is consolidating around a few platform families — Facebook's apps, Google's YouTube, and increasingly Amazon — with third-party rankings like Nielsen's becoming the currency for advertising reach.