Most AI video tools demo themselves with a single sentence: "a woman running through a city, sunset". Eight beautiful seconds come out. That is real, and it is not an ad.
An ad is not an eight-second clip. It is a sequence of scenes that follow one another and say something. The difference is in how it is produced.
Script first, footage second
The flow that works is this: you break what you want to say into scenes, you write what each scene shows and how long it runs, and then each scene is generated separately. Keep the count between two and eight — fewer than two tells no story, more than eight stops being one campaign video.
Skipping that step and asking straight for footage leaves you with beautiful frames and no edit.
Continuity is the hard part
When scenes are generated separately, the biggest risk is that the same person does not look like the same person twice. The fix is not asking the model for more, it is leaving it less freedom: define the character once, and have every scene reference that definition.
The same goes for location, lighting and wardrobe. Anything re-described per scene is anything that can change per scene.
When you dislike one scene
In the naive flow, disliking one scene means regenerating the video. What you want is to regenerate that scene alone and leave the rest of the edit untouched. That is most of the difference between "AI video" and "video made with AI". The same scene-by-scene flow, applied to one store product, is how to make an Instagram Reels video for an ikas store; the tool behind it is the product-link ad video.
What not to expect
As of September 2026 the models have come a long way; still, do not rely on them for:
Long, error-free on-screen text — short words come out, a paragraph and non-Latin characters still break
Complex hand movements with more than one object in play
Continuity over a long single take — the longer the shot, the more face, wardrobe and location drift
Exact reproduction of a brand logo
Keeping those out of the generation step — adding text in the edit, compositing the logo on a final layer, cutting a long take into two scenes — makes the result better, not worse.
The win in AI video is not that shooting gets cheap. It is that the second, third and fourth version are nearly free.