Video has become the content and advertising format of the year, with publishers, advertisers and social platforms all publicly pronouncing its importance.

Facebook, of course, has become one of video's most vocal cheerleaders. It's rolled out a number of video products, for both advertisers and consumers, recently making its Live video widely available and adding video to its ad carousel on Instagram.

Now the company is taking another step, offering two new video formats through its Audience Network, through which Facebook sells mobile ads beyond its own app and website.

The company for the first time is extending that network to serve video ads on mobile and desktop browsers, giving marketers the ability to run those ads as preroll, midroll or postroll in video content instead of just standalone ad units. Instead of direct response pitches common to mobile advertising, Facebook wants the new formats to carry branding messages.

"We're extending Audience Network to include videos from advertisers looking to drive brand outcomes," said Facebook in a blog post. "Now, in addition to watching these videos on Facebook and Instagram, people will view them on the other apps and sites where they spend their time."

It's also expanding the ways advertisers can buy video ads inside articles, or at least its own Instant Articles. Ads appear on Instant Articles by two means: through Facebook's Audience Network and in direct deals with publishers. Facebook previously allowed publishers to sell video ads inside articles themselves, but didn't support it through the Audience Network. That's now changing.

"In-article video ads will appear on mobile pages of publishers, such as Daily Mail, between paragraphs of text and play automatically when at least half the pixels are viewable," Facebook's blog post said. "In this format, the viewer must opt-in for sound." USA Today and the Daily Mail were test partners for the new products.

The moves appear designed to help Facebook compete against Google, which dominates digital advertising.

The Audience Network was introduced widely in April 2014 at Facebook's F8 conference. At the time, it was limited to apps, but in January 2016, it extended the network to the mobile web.

Mobile ad networks are well known for their direct response-type ads, and the Audience Network has been no exception. Mobile game developers, for example, often choose this type of ad format in their quest for downloads.

Direct-response ads have been the focus of the Audience Network, said Brett Vogel, product marketing manager at Facebook, but the new format differs in that the direct response video ads cannot run instream -- in other words, in the video slots before, during or after the content plays -- and instead only run in other ad slots on a site or app.

"When an advertiser comes to us and tells us their objective, they might be looking to get people to their websites, stores or app," Mr. Vogel said. "But they also want to drive brand objectives -- to build brand awareness. We're very focused on ad formats that fit the setting. The way we tend to think about that is with longer form video content, which is in-stream, these kinds of ads make a ton of sense. The experience is very much like TV."

Audience Network has the same video length requirements as Facebook Feed, said a spokeswoman, but in-stream video ads will have to be longer than 10 seconds and shorter than 30.

Facebook in its blog post said the new products can help improve return on investment. "With more places to deliver content, we can better maximize value for advertisers who want more brand exposure through video," it said. "Globally, advertisers that opt-in to the Audience Network can generate approximately 10% more incremental reach than using mobile News Feed alone. [Facebook internal data, May 2016]. Plus, we increase our ability to show the most relevant ads to each viewer. If your targeted audience spends more time in a particular app than on Facebook or Instagram, your video will be shown in that app more often."

When it comes to serving video ads on apps, mobile web and desktop, the move is, essentially, a way for Facebook to make more money serving video ads without further inundating the Facebook news feed. Though it will serve video ads on Instant Articles, users may already be accustomed to seeing video ads in them, so it remains to be seen if the additional video ads in Instant Articles will be noticeable.

Facebook has been very outspoken about its prioritization of mobile, and it shows in its revenue. In the first quarter, the company beat Wall Street's expectations, with ad revenue increasing to $5.20 billion, up 56.8% over the same period in the prior year. Mobile ad revenue surged, making up for 82% of its total ad revenue, up from 73% of the total a year earlier.

And though the company's focus on mobile remains, opening video ads on the Audience Network to desktop has the potential to bring in a significant amount of money in if its advertisers jump onboard. That, of course, also remains to be seen.

"Being able to buy video advertising on Instant Articles through the Audience Network represents an opportunity to scale up on that platform, because Facebook can scale better than publishers can," said Ian Schafer, founder-chairman of Deep Focus.

Mr. Schafer also said adding in-stream video ads to the Audience Network shows just how much Facebook is going after Google. "There are a lot of dollars flowing to video, and this gives Facebook greater access to the flowing inventory that's not in the Facebook app," he said. "It also takes Facebook's ad products and makes them look more like Google's. They're clearly locked in a battle for supremacy in that regard."

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CORRECTION: An earlier version of this article erroneously said in-stream video ads will have to be shorter than 10 seconds or longer than 30. The ads will need to be between 10 and 30 seconds long.