Facebook proved in 2016 that, after 12 years of existence, it remains the dominant force in social — and is very much still figuring things out.

In early November, on the company’s third quarter earnings call, Facebook announced a remarkable achievement: Its offerings now reach over 1 billion daily active users — and that’s on mobile alone. To put Facebook's mobile influence in perspective, Snapchat, which has dominated the social media conversation this year in a way the older Facebook hasn’t, only recently attained 60 million daily active users in the U.S. and Canada.

However, repeatedly over the past 12 months, the platform also earned the ire of marketers, media buyers and publishers alike, for things both big — including potentially swaying the election for some voters — and small.

Facebook's struggles with metrics, fake news and more deserve a second look because they underscore how digital marketing is experiencing some growing pains as it leaves behind the early days of feverish experimentation and matures into the biggest marketing channel in terms of spend. To get caught up on where Facebook stumbled in 2016 — and where they will need to improve in 2017 — check out Marketing Dive's definitive rundown: 

1.) Measurement woes

Facebook now stands as one of the world’s two biggest digital ad platforms, and continues to net the majority of its revenue from, well, ads. In that regard, the company should do the utmost to keep ad buyers and brands happy, but many were left understandably steamed when the company revealed this fall that it had severely over-inflated viewability on video ads as far back as 2014.

“The metric should have reflected the total time spent watching a video divided by the total number of people who played the video. But it didn’t,” David Fischer, vice president of business and marketing partnerships at Facebook, said in a blog post at the time. “While this is only one of the many metrics marketers look at, we take any mistake seriously.”  

Though Facebook might’ve taken the issue “seriously,” that didn’t stop three other major metric mistakes from emerging in the ensuing months. In November, following revelations about overestimated organic page reach, the company publicly apologized and committed to a new era of transparency with marketers, but misallocated data for Live streaming reactions cropped up in early December and Instant Articles miscalculations surfaced just a few weeks later.

With reports of the Media Ratings Council in talks with Facebook to audit its measurements, there might be a brighter — or at least more accurate — future in 2017.

2.) All the fake news that’s fit to print

In May of this year, Pew Research revealed that over 40% of U.S. adults now turn to Facebook as a primary news source. That striking statistic might sound like a win for publishers and for Facebook, except for the fact that a lot of that news turns out to be completely bogus.

BuzzFeed News reported in November that fake news and hoax stories on Facebook actually outperformed legitimate editorial during the election season, and Facebook might have continued to generate a ton of ad revenue from all the harmful misinformation it was distributing.

Compounding the problem was the company’s failure to address the issue in any clear manner; CEO Mark Zuckerberg essentially shrugged off accusations that his company had any hand to play in influencing the election, even as an internal task force formed to weed bad sites out of the Audience ad network.

Zuckerberg has since reversed course on his indifference, introducing a third-party fact-checking program in December and seeking out a new head of media partnerships. Here’s to hoping less trending News Feeds stories next year have headlines like “Yoko Ono: ‘I Had An Affair With Hillary Clinton In The ’70s.’”     

3.) Overshooting the mark

In an era where knowing as much about the individual consumer as possible earns a premium, is it possible to overreach when it comes to ad targeting? The answer for marketers on Facebook came as a solid “maybe” this year when Procter & Gamble, the world's largest advertiser, announced plans to peel back its ad targeting via the platform in August.

“We targeted too much, and we went too narrow,” P&G’s Chief Brand Officer Marc Pritchard told The Wall Street Journal.

While over-targeting is hardly Facebook’s fault alone, the platform couldn’t help but become a flashpoint for discussions on the subject following P&G’s admission of error. Since Facebook is so massive, it often serves as a litmus test for what is and isn’t working in the digital ad business, both the good and bad.

Given the rise of ad blockers on mobile and desktop — and Facebook’s apparent inability to stop them — there’s still a ways to go for everyone in the industry to make sure the good wins out.   

4.) So long, Atlas (or at least some of it)

If recent news about the malicious Russian bot farm Methbot — possibly the largest ad fraud scheme of all time — taught digital advertisers anything, it’s that nowhere online, not even on the biggest, most seemingly secure platforms, is safe.

In March, Facebook found that out the hard way when it had to shutter the demand-side ad buying platform it had been testing through its primary ad server, Atlas.

“We were able to deliver ads to real people with unprecedented accuracy, but came up against many bad ads and fraud (like bots),” Dave Jakubowski, head of Facebook ad technology, wrote at the time. “While we were fortunately able to root out the bad actors and only buy quality ads, we were amazed by the volume of valueless inventory.”

Facebook indeed announced plans to shutter ad serving via Atlas completely in mid-November, stating it would, perhaps unsurprisingly, pivot focus to sharpening its measurement tools instead.

5.) Copycat behavior

It may be a little unfair to only pile on the negatives, as Facebook continues to experiment with bleeding edge technologies that might lead the wave of where social is going next.

The company remains a world leader for VR and facial recognition software and has dominated the conversation around chatbots thanks to Messenger. New experiments like Caffe2Go, announced in November, hint at the creative possibilities for AI on social, and Facebook has been key in getting marketers excited about the idea of “live” with real-time audio options and Live 360, a new video format that combines immersive 360-degree views with streaming.

However, in other areas, Facebook not only showed it was a little short on new ideas but also willing to blatantly copy the competition. Snapchat in particular is clearly top of mind, as Facebook tested Snap-aping standalone apps, along with eerily familiar features for Facebook proper, Live and Messenger.

The mimicry is understandable, in some sense: Facebook, despite its massive total audience of nearly 2 billion, is struggling to attract younger demographic groups like Gen Z while Snapchat has a strong hold on their attentions. But the Facebook features that excite most — a recently unveiled Morgan Freeman-voiced AI is pretty cool — are definitively less derivative than copycat flops like Poke or Slingshot.

Hopefully, there'll be more of the new and less of the old in 2017.