It takes money, the adage goes, to make money. And Facebook is spending a lot of dollars to do just that.

The social media giant on Wednesday posted another quarter of robust revenue growth — up 41 percent in the third quarter from a year earlier, to $4.5 billion — fueled by its mobile advertising business and an increase in daily users. Net profit rose to $896 million, up 11 percent from a year ago.

The revenue and profit increases came alongside a surge in spending. Facebook’s expenses totaled more than $3 billion in the third quarter, a 62 percent leap from a year earlier, meaning that spending growth is outpacing sales growth. The company, based in Menlo Park, Calif., emphasized that it had no intention of slowing that down as it invested heavily in hiring, marketing, new technologies and other initiatives.

“We’ve made the way we do this very clear,” Sheryl Sandberg, chief operating officer of Facebook, said in an interview. “We invest.”