If Facebook's (META 1.54%) stock price run these past few days leading up to its April 22 earnings announcement is any indication, investors were expecting yet another blowout quarter. Facebook shareholders have enjoyed a nearly 5% jump in share price since close of business April 17.

Why? Because it became evident that investors and industry pundits expected Facebook to not only meet earnings-per-share estimates of $0.40, but also to surpass that lofty goal. As for revenues, the consensus estimate of slightly over $3.5 billion would be a 40% plus year-over-year improvement.

But sales and earnings aren't the only things on the minds of Facebook fans. Growth in Facebook's and its properties' monthly average users, or MAUs, along with the success of its shift to mobile, user engagement, and the previously announced increase in costs, were all worth monitoring. Based on after-hours trading, some were less than enamored with Facebook's results -- but don't be fooled.

Just the facts
Facebook announced Q1 2015 revenues of $3.54 billion, just a hair shy of the $3.56 billion expected. On anon-GAAP basis (removing one-time items), Facebook generated $0.42 per share in earnings, narrowly beating forecasts.

Like most geographically diverse companies today, a strong dollar dinged Facebook's first-quarter results. The 42% increase in last quarter's sales compared to the year-ago period would have been 49%, as per Facebook, had it not been for the impact of "foreign exchange rates." Advertising sales, the bulk of Facebook's total revenues, increased 46% in 2015's Q1 to $3.32 billion.

While just hitting analyst estimates may have taken the wind out of some Facebook fans' sails, it continues to deliver on the mobile front.

A year ago, mobile ad sales were responsible for 59% of Facebook's total revenues. Today? That figure has jumped to 73%, and that's up four percentage points sequentially. Facebook's Payments and Other Fees, home of its budding app development efforts (among other things), reported a so-so $226 million, down 5% compared with 2014's Q1.

On the spending front, soaring expenses continued. Following 2014's Q4 87% increase in overhead year over year, Facebook announced that this quarter costs soared 83% to $2.61 billion. The cost of assimilating assets including WhatsApp and Oculus while continuing to develop analytic tools for Facebook's marketing partners is adding up.

For those around last quarter, Facebook CFO Dave Wehner said investors could expect more of the same when it comes to spending. Apparently, he wasn't kidding. Not surprisingly, the jump in expenses affected income from operations and margins, both down significantly year over year.

A little icing on the cake
Even though it's the largest social-media site on the planet, Facebook is still growing its user base at a phenomenal rate. Facebook added 50 million MAUs last quarter and now has 1.44 billion. To put that into perspective, Twitter (TWTR), even at about one-fifth the size of Facebook, added 4 million MAUs last quarter. It's no wonder many investors and industry pundits are concerned with Twitter's lack of user growth; they can point to Facebook and say, "They're able to still do it, why can't you?" Good question.

Another question Twitter bears ask is about the seeming lack of engagement. Based on Facebook's daily average user growth, it doesn't have the same problem. As of Q1 2015, 936 million users access their account daily, up from 890 million just three months ago. And a lot of those logging into Facebook are doing so remotely. Facebook announced that of its 1.44 billion MAUs, 1.25 billion are mobile.

And Facebook's not the only site growing -- its properties are as well. WhatsApp added an amazing 100 million users just this year alone and now boasts over 800 million. Instagram is sitting at 300 million plus MAUs, and Facebook Messenger now has over 500 million users.

You're likely to hear somewhat muted reactions to Facebook's 2014 Q1 results. Why? Because a line drive just doesn't cut it anymore: Facebook's raised its own bar so high now that only a home run will do. That said, a 42% improvement in revenue, a 20% increase in non-GAAP earnings, impressive MAU growth, continued user engagement, and domination on the mobile front are nothing to sneeze at.