Facebook’s latest headcount: 955M and still growing

Facebook has been steadily marching toward the one-billion-user mark. Today the company announced that it is very nearly there, with 955 million active monthly users.

Today’s figure represents a 55 million-user increase since April, when the social network had just surpassed 900 million MAUs (monthly active users).

The MAU figure is Facebook’s preferred metric for describing its growth. We also got an update on daily active users (552 million, up from 526 million in April) and mobile users (543 million, an increase from 488 MAUs on mobile devices in April). MAUs and DAUs were both up around 30 percent year over year, and mobile monthly users saw a 67 percent year-over-year increase.

The reason for today’s announcements is, of course, Facebook’s quarterly earnings, and all these eyeballs add up to a lot of cash for the social network — the majority of its $1.18 billion in revenues for the second quarter, in fact.

Online marketing analysis firm eMarketer noted that Facebook is dominating the U.S. display ad market, taking the lead from Google with a 14 percent share of the total market in 2011, up from 11.5 percent in 2010.

And mobile users also represent a huge opportunity for Facebook. Mobile advertising spending in the United States climbed to a stunning $1.45 billion in 2011. Mobile advertising wasn’t a huge priority for Facebook, which rolled out its very first mobile ads earlier this year. Currently, Google claims 51.7 percent of the mobile advertising market, around $750 million, according to eMarketer.

We’ll have more coming up soon on Facebook’s earnings, growth, and stock price fluctuations, so stay tuned. For now, here’s a handy little chart showing stock prices for Facebook and a few related companies over the past month. As you can see, investors aren’t too impressed — yet. (In fact, Facebook stock hit a new low of $24 in after-hours trading today.)

Here are some more fascinating stats from today’s string of announcements:

• Revenues came to $1.18 billion, made up mostly of advertising revenues, which totaled $992 million.
• Overall, revenues were up 32 percent year over year.
• For Facebook ad campaigns, 70 percent had an ROI of 3x or better, and 49 percent showed an ROI of 5x or better.
• Facebook’s warchest of cash and marketable securities grew to $10.2 billion, including the $6.8 billion it made during its IPO.