In short
The retention graph shows where viewers leave a video, but it does not show ads. If a dip lines up with an ad slot, that is a reason to check the point, not proof. Compare the dip with the content: a topic change, a slow stretch or the end of the useful part produce the same drops. Decide across several videos, not one.
What the retention graph shows#
Studio’s Engagement tab has an audience retention report. It shows what share of viewers is still watching at each moment. A gradual decline is normal: viewers leave over time. Sharp drops and spikes are worth investigating.
Importantly, the graph is built on the video itself. Ad slots are not marked on it, and it does not separate viewers who saw an ad from those who did not.
Retention
coincidence ≠ cause
Why a dip next to an ad is not a verdict#
A good ad slot sits at a transition: the end of a chapter, after a conclusion, before a new topic. But transitions are exactly where viewers leave more often anyway: they got the answer they came for, or the next topic does not interest them.
So a dip lining up with a slot is expected even without any effect from the ad. To see whether there is a link, you need more than one point.
What to check before removing slots#
- What happens in the video at that moment. Listen to 30 seconds around the dip. The end of the useful part, a topic change or a slow stretch are common reasons to leave.
- Is there a similar dip without an ad? If other transitions in the same video show the same drops, the ad is unlikely to be the main cause.
- Does the pattern repeat in other videos? One video is chance; five videos with the same dip at a slot is a pattern.
- Where the slot sits. If it is mid-sentence or has YouTube feedback, move it anyway: how to fix the feedback.
If dips repeat at slots in the same parts of your videos (in the first minutes, say), consider placing the first slot later or choosing a lower frequency: how to choose mid-roll frequency.
How to compare before and after#
If you changed placement and want to see how it affected retention, compare carefully:
- equal periods before and after the change;
- the same videos, not different ones;
- with season and traffic sources in mind: viewers from search and from recommendations behave differently.
More on this kind of check in how to evaluate an ad placement change.
Where Monvilo helps#
Monvilo places slots at finished speech pauses, where viewers are less inclined to leave than mid-sentence. The dashboard’s Ads tab shows which videos have slots without issues and where there are “interferes” flags.
Monvilo does not replace the retention graph: view it in Studio. But if you changed placement, the dashboard marks the change on the timeline, which makes it easier to compare with retention and revenue.
Frequently asked questions#
Does the retention graph include ad time?
No. The graph is built on the video’s own timeline. Ads add no seconds and are not marked on it.
Do mid-roll ads lower retention?
Any break is a reason to leave, especially a poorly placed one. How much depends on the video, the slot and the audience. There is no single number, so check on your own videos.
Should I remove all slots if retention dropped?
No. Find the cause first: a dip is often explained by the content. Remove or move only the slots that sit at poor points.
Sources#
Checked October 25, 2026: audience retention, mid-roll ads in long videos. Dashboard screenshot: Monvilo 2.22.2 with demo data. The diagram is illustrative with no real data; the recommendations are our practical approach.