A picture may be worth a thousand words, but according to Forrester Research, "a minute of video is worth 1.8 million words." It's no wonder, then, that video recently surpassed blogging as one of the most commonly used types of content by social media marketers. Social Media Examiner's "2018 Social Media Marketing Industry Report" lists it as the second-most popular social content after visual images.

It's easy to see why video has exploded in popularity in the last few years, with 80 percent of all web traffic projected to be video in 2019. Engagement is through the roof: between 2016 and 2017, YouTube saw a 99 percent increase in branded video content views. Video content and motion graphics have proven particularly effective for educating your audience and launching new products or services. What's more, they boost conversions: 48 percent of smartphone users become more likely to make a purchase if a company includes an instructional video on their app or mobile site.

The problem is, many marketers feel unprepared to deploy video effectively. A full 77 percent say they want to learn more about video and/or live video, according to Social Media Examiner. Here are five keys to successful video marketing that you'll need to keep in mind as you launch or re-envision your video marketing strategy.

1. Keep your audience top-of-mind.

Your target audience will not only determine where you'll post your video or motion graphic -- it will also affect design style, video length, and tone. An Instagram story is very different from a YouTube video in everything from length and use of sound to orientation.

Meanwhile, different audiences have different preferences. The Interactive Advertising Bureau reports that, when it comes to video ads, millennials prefer 10-second spots whereas Generation X prefers the more traditional 30-second ad.

2. Optimize for the platform.

A motion graphic must be optimized to display well on every platform where it appears. This often requires some reformatting, but it's worth the effort.

For instance, if you're planning to use a video you've posted on YouTube for Instagram-based promotion, you'll need to make some changes. If you post it in your Instagram Story, it needs to be no longer than 10 seconds, with a vertical orientation. This will likely mean clipping one key, compelling piece of the motion graphic and editing it for the format. Meanwhile, because Twitter has the fastest scroll, when you tweet your video it needs to be visually engaging from the first millisecond.

And no matter what platform you're posting on, don't forget about mobile: 60 percent of YouTube videos are viewed on mobile devices.

3. Determine the most effective length.

Average engagement decreases the longer a video is, so if you're investing in longer-form videos, you may be wasting both time and money.

A study by video hosting and analytics company Wistia found that engagement is at its peak when a video is 1-2 minutes long. This is great news if you need 90 seconds to get your message across, because you'll get just as much engagement as if the video were just 30 seconds.

Staying within this window will ensure engagement, but how do you decide between 10 and 120 seconds? A lot of it depends on your content: how are you going to tell your story? How much information do you need to include? What content is most likely to inspire viewers to learn more? Other factors include budget and audience; I've already discussed what certain demographics prefer above.

4. Choose the right design style for you.

Many brands use live video because their brand has lots of it to share. After all, if you're selling cars, there's no better strategy than those high-speed road-test videos. But if your brand is telling a more complex story, or doesn't have much live-action video to share, motion graphics may be a better fit.

With the support of strong content-writing and design teams, motion graphics can be the optimal choice for any brand or message. Motion graphics can combine data visualization, illustration, voiceovers, sound effects, and music to deliver meaning -- which means they can be fully customized to whatever you're trying to say.

A third option is live-action video with animation overlay. This could be ideal if you're showing a process or event that could benefit from a little more information. For an example, check out this video from "The Art of Making," which shows a guitar being made from scratch and overlays data about the materials and process along the way.

5. Opt for custom music and sound design.

As I explain in a recent video tutorial on sound design in motion graphics, sound design is a combination of custom music and sound effects that complement the visuals and narration of a motion graphic. They rise when the tension rises, punctuate key moments, and create tone and atmosphere. Stock music can't come close to boosting the overall quality and effectiveness of your motion graphic in the same way.

Use these five strategies and you'll be sure to attain optimal engagement for your motion graphic or video on any platform.