Image-first platform Pinterest is making a big move into video.

The company on Wednesday introduced Promoted Video ads, allowing users to expand its existing, animated Cinematic Pins to access a full auto-play video with sound. Brands can display six Buyable Pins beneath each video as it plays.

According to two different agency executives, Pinterest is offering the units for a minimum of $500,000, with CPMs -- or cost per thousand impressions -- ranging from $15 to $20.

Video, as Pinterest puts it, will now be a "core part" of its user experience.

"This is a focused effort from the company to make a much bigger bet on video," said Jon Kaplan, head of global sales at Pinterest. "Things are going to change pretty dramatically in the coming quarters as we get more serious on the core user experience, ingest much more video content than we've ever done before and by making video much more discoverable on the platform."

Video has been on Pinterest for at least five years, but it's certainly not something often associated with the platform. Other social media companies like Facebook, for example, made video a core part of its user experience before introducing video ads to its audience.

Agency executives said Pinterest was moving in the right direction.

"Pairing video with ecommerce is a smart move as it leads to a distinct offering in the market and further cements the story Pinterest wants to tell of tying creative to commerce in one platform," said Noah Mallin, senior partner and social practice lead at MEC. "Ultimately, platforms have to continually evolve the user and advertiser experience. The danger in not innovating like this is stagnation."

Promoted Videos are currently only available to larger advertisers who work directly with Pinterest's account teams in the U.S. and U.K. Initial buyers include Kate Spade, BareMinerals and Behr Paint.

The company added it will use many of its targeting capabilities to show relevant videos ads based on what a user's interest are.

"The big promise Pinterest had for a long time is that you would be able to bring the top and the bottom of the funnel together," said one high-level agency executive who asked not to be identified to protect industry relationships. "And Pinboards were that initial thing that could lead to an actual purchase that would happen directly on the site."

"There was some indication that was actually happening, but I don't think you've seen the build on that," the executive added. "What they haven't been able to do, but they're getting closer to this, is embracing things like video, which still isn't a big part of the platform as it is in other places. And I think video is where consumers are starting to gravitate toward."

Pinterest acknowledged that it has room to grow in video. "Candidly, I think video is an opportunity that we have to build upon the base case of the usage on the platform," Mr. Kaplan said. "A big part of this is getting the content from the media companies onto our platform and finding the right distribution outlets for that."

"Before now, we haven't focused on that and we haven't found ways for people to discover content in a really qualified way that encourages more viewership and specifically promotes this kind of content," he added.

The company said it isn't planning any push to encourage users to upload video to the platform, but instead will ask top-tier publishers and media companies to share their video assets onto Pinterest. These will likely include videos that show how to make certain food dishes, or will offer fashion or makeup tips.

"Publishers are really anxious for us to ingest their content in a structured way and make it discoverable," Mr. Kaplan said. "It is not just good enough to have it be on the platform. It has to be discoverable to that individual's interest and there are a variety of different ways that we're thinking about evolving the discovery mechanism beyond what you are seeing today."

Earlier this month, Pinterest said it would be rolling out its own native video player, something it will look to use as it builds up video content on its platform.

"If you asked me a year ago, I would have been lukewarm about how video would go on Pinterest," said Kate Rush Sheehy, strategy director at R/GA. "But I think when you look at what has happened with Cinematic Pins, the results we've seen from our clients here are actually pretty tremendous in terms of how people are engaging with them."

"Given the way consumers interact with Cinematic Pins, I think it makes video a more interesting proposition," she added. "You see platforms like Instagram updating and evolving themselves with Instagram Stories. Pinterest has to find other ways to stay interesting and make sure that experience is leaving consumers with what they expect to see."

Pinterest says its users are already engaging with video at a significant rate, adding that the number of videos saved by users to view later on the platform has increased 60% year-over-year. Still, when asked to share numbers that would put the increase in perspective, Pinterest declined to comment.

The platform saw about 92 million U.S. visitors during the month of July, according to ComScore, up 21% from the same time a year ago.