eMarketer predicts Snapchat's monthly US users will decline by 2.8% to 77.5M in 2019, capturing 37.9% of US social media users, down from nearly 40% in 2018
Instagram will benefit, adding nearly 19 million users by 2023 — Following its unpopular redesign, Snapchat has been struggling to gain users in the US.
Context & Ripple Effects
Snapchat's slide has been building for over a year: a YouGov survey found brand sentiment among 18-34s fell 73% after the redesign, and Q2 2018 brought Snap's first daily-user loss since its founding. eMarketer's new forecast turns that engagement damage into an outright decline in monthly US users — 2.8% down to 77.5M, with Snapchat's share of US social media users slipping below 38% from nearly 40%.
The beneficiary is Instagram, which eMarketer projects will add nearly 19 million US users by 2023 — echoing its earlier finding that Facebook was bleeding young US users while Instagram grew. But even that runway is narrowing: eMarketer later reported Instagram's own US growth rate dropped into single digits at 6.7%, down from 10.1% in 2018.
First-order effects
- Snap enters 2019 with a shrinking US monthly base of 77.5M and a falling share of US social users, weakening the audience pitch it makes to advertisers just as it tries to recover from the redesign-driven sentiment collapse.
- Instagram captures the users Snapchat sheds, with eMarketer projecting nearly 19 million additional US users for Instagram through 2023.
Second-order effects
- Advertisers weighing Snap against Instagram face a widening reach gap in the US, pressuring Snap on pricing and pushing more social video spend toward Facebook's family of apps.
- Instagram's gain is partly a rotation, not pure market expansion — with its own growth rate already halved to 6.7% per eMarketer, both platforms end up competing harder for the same finite US audience.
Third-order effects
- If the pattern holds, the US social market shifts from land-grab growth to zero-sum churn, where product missteps like Snapchat's first-ever DAU decline translate directly into permanent share transfer between incumbents rather than temporary dips.
- A maturing US user base raises the stakes on retention and platform design decisions, since there are fewer new users left to offset losses — a dynamic eMarketer's forecasts track across both Snap and Instagram.
The trend: US social media is moving from user growth to user reallocation, with a saturated audience forcing incumbent platforms like Snapchat and Instagram to fight over share rather than expand the pie.