Social networking juggernaut Facebook reported second-quarter earnings on Wednesday. The company's advertising revenue is up 47 percent year-over-year, from $6.2 billion to nearly $9.2 billion. The vast majority of that comes from mobile advertising, which went from 84 percent to 87 percent of total revenue. Monthly active users numbered two billion in June, for the first time, and daily active users hit 1.3 billion. Both metrics grew 17 percent year-over-year.

In other words, for every percentage point of user engagement growth, advertising revenue grew 2.7 percent. That's the mark of a company that is monetizing its users more and more effectively over time. However, all three of the executives on the earnings call -- CEO Mark Zuckerberg, COO Sheryl Sandberg, and CFO David Wehner -- cautioned investors to be aware that Facebook expects the impact of increasing "ad load" (the amount of ads in the News Feed and other content streams) to slow as the company reaches the limit of how many ads users will tolerate. Meanwhile, revenue growth from newer products like Messenger is expected to maintain a leisurely pace.

CEO Mark Zuckerberg said on the earnings call, "We're proud of the progress we're making," adding that "it also comes with a responsibility" for Facebook to have a positive impact on the world. "Our new mission is to bring the world closer together," he reminded the listeners. "A big part of this mission is building community." Zuckerberg talked about how Facebook groups can have an impact on people's daily lives, which is an aspect of the Facebook experience that he wants to improve and strengthen.

Zuckerberg also talked up the potential of artificial intelligence to improve Facebook's products. The CEO -- who in a recent Facebook Live chat chided Elon Musk for his "irresponsible" fearmongering around AI, explained, "I expect AI to change the way that we do business in some important ways." He gave the example of software flagging content that violates Facebook's policies before it could start spreading, without any human involvement needed.

However, Zuckerberg said that "the really big improvement" from AI will be when algorithms can know what content you'll be interested in, from all over the web, rather than just relying on your social network and "liked" pages to surface articles and videos that interest you.

COO Sheryl Sandberg's comments were focused firmly on the business side of Facebook. "Our first priority is helping businesses leverage the power of mobile," reiterating that companies need to reach consumers where they are, which is commonly in the content streams of apps like Facebook, Instagram, and even WhatsApp. Zuckerberg mentioned earlier that both Instagram and Whatsapp's Stories features have 250 million daily active users, respectively. Sandberg announced that more than 70 million businesses use Facebook, while Instagram hosts more than 15 million business profiles.

Sandberg also talked about the importance of video to Facebook's advertising business. She said that people are looking for "snackable content," and added, "Native mobile videos ads typically out-perform more traditional ads." CFO David Wehner said later that "video is the most engaging experience that we can offer" and indicated that Facebook is following the pull of consumer behavior.