Social media giant Facebook reported big jumps in revenue and profit for the third quarter, but warned that revenue growth will decline in Q4.

Sales jumped 56 per cent year-on-year in the July-September period to $7.01 billion, while net income surged 166 per cent to $2.38 billion.

Daily active users averaged 1.18 billion in September, up 17 per cent year-on-year. 92 per cent of that base (1.09 billion) were mobile users, a jump of 22 per cent over the same period.

That proportion is slightly higher on a monthly basis. Facebook’s monthly active users came in at 1.79 billion as of September 30 (up 16 per cent year on year), with 93 per cent of them (1.66 billion) coming via mobile.

And mobile is continuing to dominate revenue at Facebook. Mobile advertising revenue represented 84 per cent ($5.7 billion) of advertising revenue for the third quarter of 2016, up from 78 per cent in the third quarter of 2015.

“We had another good quarter,” said Mark Zuckerberg, Facebook founder and CEO. “We’re making progress putting video first across our apps and executing our 10 year technology roadmap.”

However, in a call with analysts, Facebook CFO David Wehner said ad growth would likely slow “meaningfully” due to limits on “ad load,” or the number of ads that Facebook can put in front of customers without alienating them.

He also said 2017 would be a year of aggressive investment with a substantial increase in expenses. Facebook plans to make large investments in hiring and data centers next year.

Zuckerberg added on the call that 40 million people now use Internet.org, the company’s free mobile internet service, to get online, up from 15 million last year.

The company said it hired 1,200 employees in the last quarter, boosting its total workforce to 15,700.