What Is Outstream Video?
Outstream video is a digital ad format that plays video ads outside of video content. Rather than appearing before, during, or after a publisher’s video player, outstream ads expand within text articles, news feeds, sidebars, or app content, auto-playing when the unit enters the user’s viewport and pausing when it scrolls out of view. The format gives advertisers access to video inventory on publishers who produce no video content of their own.
How Outstream Video Works
An outstream unit is delivered through a lightweight JavaScript tag embedded by the publisher. When a reader scrolls to the designated placement, the player initializes and begins playback. Most implementations default to muted audio, with the option to unmute by tapping or clicking. The ad pauses automatically when it leaves the viewable area and resumes if the user scrolls back. Once the ad completes or the user closes it, the unit collapses and the surrounding editorial content closes the gap.
This behavior makes outstream highly dependent on viewability standards. The IAB defines a video ad as viewable when at least 50% of its pixels are in view for two continuous seconds. Outstream vendors typically report a “viewable impression” only after this threshold is met, making the metric more meaningful than a raw impression count.
Types of Outstream Placement
In-Read
The most common outstream format. The video unit appears inline between paragraphs of editorial text, mimicking the reading flow. Publishers using this format include major news outlets running programmatic demand through providers like Teads, which built its inventory model almost entirely on in-read outstream.
In-Banner
A video creative runs inside a standard display banner slot (typically 300×250 or 300×600). The unit uses existing display inventory without requiring a dedicated video placement. Performance tends to be lower than in-read because users associate banner slots with static display ads and often ignore them.
In-App and In-Feed
Mobile apps and social platforms serve outstream units between content cards in scrollable feeds. Meta’s and TikTok’s feed video ads share structural similarities with outstream, though those platforms operate closed ecosystems. Open-web in-feed outstream typically runs through programmatic advertising supply-side platforms.
Interstitial
A full-screen or near-full-screen video unit triggered between page transitions in mobile apps. It generates high viewability scores and completion rates, though frequency capping is essential to avoid user frustration.
Outstream vs. Instream
| Attribute | Outstream | Instream |
|---|---|---|
| Placement | Text content, feeds, sidebars | Within a video player |
| Publisher requirement | None (no video content needed) | Requires existing video inventory |
| Audio default | Muted | On (pre-roll) or off (varies) |
| Skip option | Often closeable immediately | 5-second forced view (skippable pre-roll) |
| Inventory scale | High (any text publisher) | Limited to video publishers |
| Average CPM | $8–$18 | $15–$35+ |
Instream pre-roll ads generally deliver stronger brand recall because users are already in a lean-forward video-watching mindset. Outstream trades some of that attention quality for reach and cost efficiency, making it useful for campaigns where video inventory supply would otherwise constrain scale.
Key Metrics and Benchmarks
Viewability Rate
The percentage of served impressions that meet the IAB viewability threshold. Industry benchmarks for outstream in-read typically land between 55% and 75%, compared to 40% to 60% for standard display.
Video Completion Rate (VCR)
The percentage of viewable impressions that play to 100%. Because outstream defaults to muted and allows the user to scroll past, VCR for 15-second outstream units tends to range from 30% to 55% on desktop and 25% to 45% on mobile. Shorter creatives consistently outperform longer ones in this format.
Cost Per Completed View (CPCV)
A more precise buying metric than a flat CPM, CPCV calculates the true cost of delivering a full video view.
Formula:
CPCV = Total Spend / Number of Completed Views
Example: A brand spends $25,000 on an outstream campaign delivering 500,000 viewable impressions with a 40% VCR. That yields 200,000 completed views and a CPCV of $0.125. The same spend on a premium instream buy at a $30 CPM with 70% VCR delivers roughly 833,000 impressions and 583,000 completed views at a CPCV of $0.043. The instream placement wins on efficiency per completion, which is why outstream is often positioned as a reach extension rather than a direct substitute.
Creative Considerations for Outstream
Because most outstream plays without audio, the creative must communicate the message visually. Silent-first design is not optional in this format.
Muted-First Creative Principles
- Caption everything. Burned-in captions or text overlays are standard practice. Unilever’s marketing teams applied this discipline across outstream campaigns for brands like Dove and Hellmann’s, designing video assets where the core message is legible in silence within the first three seconds.
- Win the first two seconds. The opening frame carries disproportionate weight. In a muted autoplay environment, the first one to two seconds determine whether a user pauses to watch or scrolls past. High-contrast visuals, recognizable brand elements, and motion that implies something interesting is about to happen all improve retention.
- Go vertical on mobile. While traditional video runs at 16:9, mobile-first outstream units often perform better in 1:1 or 4:5 formats, which occupy more vertical screen space in a feed without requiring the user to rotate their device.
When Outstream Makes Sense
Outstream suits campaigns where video reach needs to extend beyond the supply available on YouTube, connected TV, or premium streaming. For a mid-market brand running a product launch on a modest budget, outstream in-read through a native advertising or programmatic partner can generate millions of viewable video impressions. The CPMs are simply not available on instream inventory at that scale.
It is less suited to campaigns where brand safety requires tight editorial control or where the product category demands high audio engagement. Financial services and pharmaceutical advertisers often find that instream, with its captive pre-play audience, delivers better message comprehension despite the higher cost.
Retargeting use cases represent a middle ground. When an audience segment has already demonstrated intent through site visits or search behavior, outstream can reinforce the message at scale and low cost. No premium video environment required.
Outstream and Brand Safety
Because outstream units appear on any publisher running the ad tag, contextual alignment and brand safety filtering are essential. Supply-side platforms typically offer URL-level blocking, category exclusions, and third-party verification through vendors like Integral Ad Science and DoubleVerify, two of the largest independent ad verification companies in the industry. Advertisers running outstream programmatically should apply inclusion lists or at minimum verified-publisher filters rather than running fully open exchange inventory.
Frequently Asked Questions
What is outstream video advertising?
Outstream video advertising is a format where video ads play within text-based content rather than inside a video player. The ads auto-play when they enter the user’s viewport and pause when scrolled out of view. Publishers do not need to produce their own video content to run outstream placements.
How does outstream video differ from instream video?
Instream video plays inside an existing video player, before, during, or after publisher-owned video content. Outstream plays within editorial text, app feeds, or sidebars and requires no video player. Instream typically delivers higher brand recall and commands higher CPMs ($15–$35+), while outstream offers broader reach at lower cost ($8–$18 CPM).
Does outstream video play with sound?
Outstream video defaults to muted playback. Viewers can unmute by tapping or clicking, but most impressions are watched silently. Effective outstream creative communicates the core message visually within the first three seconds, without relying on audio.
What is a good video completion rate for outstream?
A video completion rate (VCR) of 30–55% is typical for 15-second outstream units on desktop. Mobile benchmarks run slightly lower at 25–45%. Shorter creatives consistently complete at higher rates in the outstream environment.
When should advertisers use outstream video?
Outstream is best suited for campaigns that need to extend video reach beyond YouTube, connected TV, or premium streaming inventory. It works well for brand awareness and retargeting at scale. It is less effective when audio is central to the message or when brand safety requires tight editorial control.