"And on top of that advertising revenues also look relatively solid. Q1 is a seasonally weak quarter for the advertising market and there's obviously a significant impact coming from foreign currency with over half or approximately half of Facebook's revenues coming from overseas," she added. "So overall I'm pretty comfortable with these numbers."
The company's monthly active users (MAUs) were 1.44 billion in March—a 13 percent year-over-year rise. Mobile MAUs were 1.25 billion for that month. Both of those MAU figures topped StreetAccount consensus estimates of 1.43 billion and 1.23 billion, respectively.
"This thing is a rocket ship, it's almost at 70 percent mobile. The company made a promise, they executed on it. This thing goes higher," "Shark Tank" investor Kevin O'Leary said on "Closing Bell."
With Wednesday's announcement the social media giant's monthly user number officially surpassed the population of China.
CEO Mark Zuckerberg described Q1 as "a good quarter and a good start to the year," highlighting the strong mobile growth (including more than one billion mobile searches every day).
Read More7 takeaways from Zuckerberg's impromptu Q&A
Those mobile gains led Facebook and its Instagram app to control more than one out of every five minutes that U.S. users spend on mobile, COO Sheryl Sandberg said on the webcast. (The company said that Instagram has over 200 million DAUs, spending an average of 21 minutes each day.)
Zuckerberg claimed that Facebook had the largest mobile audience in the world, promising that the company is continuing to capitalize on the shift to mobile use.
Facebook CFO David Wehner told CNBC after the release that the first quarter was a major engagement story, with DAUs representing about 65 percent of MAUs—a record level for the company.
Zuckerberg also focused on the firm's messaging efforts, saying that more than 45 billion messages are sent daily. He called this sector a "big priority" for the company. The CEO later said he is not inclined to combine the firm's WhatsApp application with Facebook Messenger, saying that each program sees different use cases.
Video, meanwhile, is seeing "good progress," Zuckerberg said, adding that the company posted more than 4 billion daily video views.
On the revenue front, the $3.54 billion figure represented a 42 percent increase over $2.50 billion from the year-ago period. The firm said it would have seen a 49 percent increase if not for a foreign exchange impact.
Advertising revenue was $3.32 billion for the quarter, with mobile representing about 73 percent of that figure, the company said. Ad sales had totaled $3.59 billion the prior quarter, but Q1 is a traditionally light period for the industry: Analysts had expected Facebook to only post $3.28 billion during the reported period, according to StreetAccount.
The growth in advertising revenue is attributable to the shift in mobile and video, Sandberg said. But even the largest marketing clients are not yet spending 5 percent of their budgets on Facebook, she said, so there is room to grow.