Facebook's CC: Messenger users top 200M; slower ad growth expected

|About: Facebook (FB)|By:, SA News Editor

Over 200M of Facebook's (FB) 1.28B MAUs use Facebook Messenger, Mark Zuckerberg shares on the Q1 CC. That figure, which comes as Facebook begins requiring mobile users to download the standalone Messenger app to use it, suggests Messenger's user base is on par with Instagram's and ~40% of WhatsApp's. (CC live blogs I, II)

Outgoing CFO David Ebersman notes headcount rose 39% Y/Y in Q1, and expects GAAP costs/expenses will grow 35%-40% in 2014; GAAP growth was 32% in Q1, and non-GAAP growth 26%.

Ebersman also warns Y/Y ad sales growth (82% in Q1) will slow meaningfully going forward. Facebook's 2014 revenue growth consensus (also accounts for payments/other revenue) was at 44.6% going into earnings.

Sheryl Sandberg cautions Facebook's auto-play video ads (launched last month amid high expectations) won't be a major contributor this year. On the other hand, she notes use of Facebook's custom targeting ad tools has grown 10x Y/Y, boosting ROI (and with it, ad prices).

Though accounting for just 16% of Facebook's MAU base, North America produced 47% of Facebook's Q1 revenue, down just slightly from Q4's 48%. Facebook's North American ARPU ($5.85, up $2.35 Y/Y) remains well above its ARPUs for Europe ($2.44, up $0.84), Asia ($0.93, up $0.29), and elsewhere ($0.70, up $0.20).

FB +3.7% AH. Q1 results, details, slides.