Image source: Facebook

Facebook (NASDAQ:FB) had a fantastic 2015. The business progressed nicely in all key segments and the stock soared 36%. Here's a look at Facebook's journey in 2015, told through some of the key storylines of the year.

"Internet Ad Growth Is Surging, and Facebook Is the Big Winner" --, Dec. 1
Digital advertising grew at a year-over-year rate of about 19% -- the fastest growth rate in four years -- said a report released in October by the Interactive Advertising Bureau. Even better, Facebook appears to be the clear beneficiary of this surging growth.

The IAB report showed that mobile revenue, social media advertising, and digital video revenue -- all areas where Facebook is becoming increasingly dominant -- soared 56%, 51%, and 39%, respectively. That bodes well for Facebook in 2016 -- and beyond.

"Facebook, Messenger Shine in Nielsen's Top Apps of 2015" --, Dec. 23
For a network-based business that depends on scale and ubiquity, it's vital to maintain prominence among users. Fortunately for Facebook, that certainly remains the case, with its flagship Facebook and Messenger apps placing first and third, respectively, on Nielsen's list of top smartphone apps of 2015. Facebook-owned Instagram also cracked the top 10, coming in at No. 8.

And its not just total users where Facebook excelled. Messenger also posted the highest year-over-year user growth at 31%, with Instagram enjoying a 23% increase, coming in third and just behind Apple Music at 26% user growth.

With its global user base continuing to expand at an impressive rate, Facebook's network effects are growing stronger by the day.

"Why Facebook Inc's Instagram Could Be Even Bigger Than Expected" --, Oct. 15
Facebook CEO Mark Zuckerberg's decision to purchase Instagram for $1 billion in 2012 is looking more and more like one of the biggest steals of the century.

The photo-sharing network is growing at a torrid pace, and Wall Street analysts are ramping up their predictions for just how large Instagram can become.

Wall Street's estimates reach as high as $6 billion in annual revenue for Instagram by 2020. For perspective, Alphabet's (NASDAQ:GOOG)(NASDAQ:GOOGL) popular YouTube property is expected to have generated about $1.5 billion in net revenue in 2015.

As Instagram ramps up its monetization efforts, investors can expect the photo app to drive a larger portion of Facebook's profits in the years ahead.

"WhatsApp hits 900 million users" --, Sept. 4
Unlike Instagram, Facebook's blockbuster $19 billion acquisition of WhatsApp has yet to produce much in the way of revenue. However, the popular messaging app continues to enjoy exploding user growth.

With its user base now approaching the 1 billion threshold, which CEO Mark Zuckerberg once noted as the level when a product becomes "interesting," we may soon see Facebook unveil its monetization strategy for WhatsApp. If it proves effective, that should only add fuel to Facebook's surging profits.

"Facebook Inc's Oculus Could Be Much Bigger Than You Think" --, Aug. 1
Not to be outdone, Facebook's most recent big acquisition is also making headlines. Skeptics questioned the benefits of acquiring Oculus -- a leader in virtual reality technology -- for $2 billion in 2014. However, recent reports are projecting that virtual reality hardware could explode into a $3 billion market by 2020, with the total VR industry approaching $30 billion during that time. As such, it's beginning to look like Oculus may turn out to be another example of excellent capital allocation by Mark Zuckerberg and his team on behalf of Facebook shareholders.

"Every Facebook Employee Is Encouraged to Create Something That Kills Facebook" --, Jun. 25
For a company that relies on technological innovation as much as Facebook, the threat of disruption is a constant concern. That's why I was so pleased to see this headline, as well as read Fool writer Adam Levy's analysis on the topic.

The belief that, "If we don't create the thing that kills Facebook, someone else will" is at the core of the company's culture. It drives management to experiment with new products and remain on the hunt for emerging technologies that can be added to Facebook's arsenal. That helps explain Facebook's aggressive moves to acquire Instagram, WhatsApp, and Oculus. It also explains why innovation is alive and well at Facebook, and how the company continues to delight users and shareholders alike.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.