When Facebook announced recently that it would be cutting back on the content it serves in its newsfeed from publishers and brands in favor of more content from family and friends, the publishing and content marketing worlds let out a collective gasp.

Publishers who rely on the enormous traffic that Facebook drives to their content, and the content marketers that produce that content, have been scrambling to figure out how Facebook's latest algorithm tweak will impact views and engagement with one of the fastest-growing types of content they produce today: Video

And what's Facebook's verdict on video? Here's what Adam Mosseri, Facebook's vice-president in charge of newsfeed, recently told Wired's Fred Vogelstein: "There will be less video. Video is an important part of the ecosystem. It's been consistently growing. But it's more passive in nature. There's less conversation on videos, particularly public videos."

According to an extensive analysis of 33,000 videos on Facebook conducted by Wochit, a video creation tool used by several major publishers, Facebook was already tweaking its algorithm throughout 2017, well before its most recent announcement. These changes led to declines in Facebook views per video of 8 percent in the third quarter of the year, followed by an additional 15 percent decline in the fourth quarter, according to Wochit.

In their report, Wochit reveals four essential strategies that can help boost views and engagement with your videos and, perhaps, even make some of them go viral.

1. Square is the winning format.

While not yet the majority of produced videos, this format consistently shows a significant advantage over other aspect ratios, in particular, the increasingly important "comments" metric.

Square video, which provides a better viewing experience on mobile devices, significantly outperforms horizontal videos across all engagement metrics. Wochit reports that the share of square videos produced using its video creation tool increased every quarter in 2017, growing from 26 percent of all videos in Q1 to 50 percent in Q4.

2. Longer videos get better results.

Wochit notes that since the majority of social videos are between 30 and 60 seconds, they hold the highest share of total views. However, according to their analysis, videos longer than 90 seconds have considerably higher per-video metrics. "Indeed in 2017, videos over 90 seconds received 52.1 percent more shares and 48.2 percent more views than the average of all videos."

Publishers apparently caught on to this trend, increasing the length of the videos they posted throughout 2017. "In Q1, only 12.6 percent of Facebook videos fell in the 90-plus second category, and by Q4, that number had reached 22.1 percent," according to Wochit. And it's a trend they predict will continue in 2018. 

3. The number "7" works best in video titles.

Wochit found that while more Facebook video titles featured the number 5 or 10, video titles that incorporated the number 7 generated the most views.

4. Appeal to positive emotions.

Wochit also analyzed the top 20 videos created using its tool in 2017. These viral hits were viewed more than 576 million times and shared over 7.7 million times. 

According to Wochit's analysis, 85 percent of the top 20 viral videos that were produced using its tool in 2017 were emotional, like this inspiring video about a community that pulled together to buy a man a new car, which has been viewed more than 93 million times on CBS News's Facebook page. 

People are looking for videos that make them feel better about themselves and the world they live in. Unsurprisingly, 90 percent of the top 20 videos that Wochit analyzed featured positive stories, like this video about a man releasing a previously ill swan back into the water, which has been viewed over 82 million times.