Social network Facebook (NASDAQ:FB) has made quite a comeback in 2019 after getting slammed in the second half of 2018. Shares are up nearly 50% year to date.

Of course, such a strong run-up means the pressure is on when the company reports earnings. This is why investors may want to mark their calendars for July 24, when it posts its second-quarter results after market close. 

Ahead of this quarterly update, here's a preview of some areas to watch.

Facebook CEO Mark Zuckerberg discussing the company's 10-year road map at F8 2018.

CEO Mark Zuckerberg. Image source: Facebook.

Revenue growth

Facebook beat expectations for its top-line growth when the company reported its first-quarter results in April. Revenue jumped 26% year over year to $15.08 billion, coming in ahead of an average analyst estimate for revenue of about $15 billion.

But investors should note that even though Facebook beat top-line expectations, the growth rate highlights a meaningful deceleration compared to growth seen in previous quarters. Revenue in the third and fourth quarters of 2018 increased 33% and 30% year over year, respectively.

Did revenue growth decelerate even more in Q2? Probably. Management said in its first-quarter earnings call that it expected revenue growth to continue to slow down sequentially throughout the year. 

Operating expenses

Facebook's operating expenses have been surging at a much faster pace than the company's revenue, pressuring its gross profit margin.

Expenses rose 80% year over year in Q1, hitting $11.8 billion. But this included a $3 billion accrual related to an inquiry from the Federal Trade Commission about the company's user data practices. Adjusting to exclude this one-time expense, operating expenses still increased 34% year over year.

Investors should expect more sharp expense growth in Q2, as management guided for full-year expenses to rise 47% to 55% year over year, or 37% to 45% when including the $3 billion one-time accrual expense.

Users

Finally, investors should check on Facebook's user growth.

Management said in the first-quarter earnings call that a total of 2.7 billion unique users were now using Facebook, Instagram, WhatsApp, or Messenger each month, with 2.1 billion people using them on a daily basis. Did these figures keep moving higher in Q2?

The company's daily active user growth on its Facebook platform is important, too. Though this figure includes some duplicate accounts, investors often use it to gauge the health of the company's core platform. First-quarter daily active users increased 8% year over year. Look for similar growth in the key metric in Q2.