Adding Reels-specific creative to usual video ads: −23% CPA
Commentary byROASArchiveOur analysis, not theirsProse ran a Meta A/B test that added an ad set of video built for Instagram Reels next to its usual video ads, and the combined cell had a 23% lower CPA than the usual ads alone.
Instagram published the case study. No absolute costs are shared.
- CPA: 23% lower for the cell with the usual ads plus the Reels ad set than for the control.
- The 23% is for both ad sets together, so it does not show how the Reels ads did on their own.
- No absolute CPA, spend or conversion count is shared, so the size of the test is unknown.
The change
Before
The control campaign ran Prose's business-as-usual video ads across six or more Meta placements. That video was already vertical, with text overlays and captions for sound-off viewing.
After
The test campaign kept the same usual ads in the same placements and added a second ad set with full-screen 9:16 video made for Reels, using fast cuts and transitions, delivered in the Reels placement.
Our reading: why it likely worked
Our interpretation, not the advertiser's claim.
- Adding the Reels placement with its own creative opened up more inventory and new people, so the campaign had more room to find buyers.
- Video made for Reels, with fast cuts and full-screen framing, fits the pace of the feed better than ads adapted from other placements.
Caveats: This is a Meta-published Instagram case study about its own placement, so it is vendor-reported. It was an A/B test in Meta Ads Manager run in February 2022 in the US, but the test cell changed two things at once (adding the Reels placement and Reels-specific creative), and spend and conversions are not shared.
How to run this in your account
- Hypothesis
- If we add an ad set of 9:16 video built for Reels next to our usual video ads, then CPA will drop because the Reels placement gets ads that fit it and feel native.
- Primary metric
- CPA
- Guardrails
- Thumb-stop or 3-second view rate
- CTR
- Conversion rate
- Who should try it
- Brands on Meta that run the same video across placements and don't yet have creative made for Reels. Prose's usual ads were already vertical, so this is not only a fix for horizontal video.
Who got the result
Instagram · Prose published this result (Platform success story). The numbers are theirs; the summary and commentary on this page are ours.
Questions
Does adding Reels-specific creative lower CPA?
In this Meta-reported A/B test, Prose's campaign with a Reels ad set added to its usual video ads had a 23% lower CPA than the usual ads alone.
It is one brand and vendor-reported, so test it yourself.
What aspect ratio should Instagram Reels ads use?
Reels are full-screen vertical, so 9:16 fills the screen.
Prose built its Reels ads in 9:16 with fast cuts rather than relying only on its usual video.