AI UGC for Google Demand Gen Campaigns 2026: Format-Specific Creative for Discover, YouTube Shorts, and Gmail

Google Demand Gen replaced Discovery Ads in 2023 and by mid-2026 is the largest visual-first Google surface for e-commerce brands running upper-funnel spend. It is the campaign type where UGC-style creative meaningfully outperforms polished brand assets, because the placements — Discover feed, YouTube Shorts, Gmail promo — are visual scroll surfaces first and shopping surfaces second. This is the creative playbook per placement for 2026.

What Demand Gen actually rewards in 2026

Google's Demand Gen ranker mid-2026 favors three signals on the creative side: high-CTR thumbnail composition on Discover, watch-through on YouTube Shorts, and open-rate lift on Gmail promo cards. All three are best served by creative that reads as native to the surface — not as a repurposed feed asset from Meta.

Discover feed: reads like a Pinterest / Reddit hybrid. Wins on curiosity-gap thumbnails and person-with-product close-ups. Loses on packshots and heavy overlay text.
YouTube Shorts: reads like TikTok. Wins on first-second visual hook with the person on camera. Loses on brand-first intros or logo bumpers.
Gmail promo tab: reads like an email preview. Wins on faces + product + short benefit copy. Loses on heavy design or product-only imagery.

Discover feed creative

Discover accepts 1:1 (square) and 1.91:1 (landscape) images plus 1200×628 landscape and 1200×1200 square specifically. The best-performing AI UGC pattern is a persona-with-product photo shot at eye level, in a scene that matches the audience's life (kitchen, gym, bathroom, outdoor cafe), with visible product but no overlay text. Discover users are in a “curiosity scroll” state — ad-copy overlays kill the native feel and drop the CTR.

Batch composition for Discover:

6–10 variants per persona×product combination
Three scene families (e.g. home / outdoor / lifestyle-in-use)
Two composition axes: person + product close-up, and product-in-scene with persona in background
Both 1:1 and 1.91:1 outputs generated from the same session

YouTube Shorts creative

Shorts placements inside Demand Gen require 9:16 vertical video. AI UGC video via Animateworks well here — a 6–15 second talking-head short with the persona introducing the product, in vertical framing, with subtle motion. The first second is the entire test — if the persona's eyes are locked to the camera and the product is on-screen, watch-through is meaningfully higher than for brand-first opens.

Batch composition for Shorts:

3–5 hook variants per persona×product combination
Short lengths: 6s (highest completion), 15s (highest conversion)
Storyboard-driven multi-frame variants using storyboards so the persona stays consistent across the 15s
Captions burned-in for sound-off viewers (~85% of Shorts watch time is sound-off)

Gmail promo tab creative

The Gmail promo tab creative is the underrated Demand Gen placement. It renders as an email-preview card at the top of the promo tab, and the AI UGC pattern that wins is a persona's face + product + a short benefit line. Google's spec is 300×600 or 300×1200 for the visual asset; 4:5 portrait AI UGC crops cleanly to these dimensions.

Batch composition for Gmail:

3–5 face-first variants per persona×product combination
Portrait crops (4:5 native from ppl.studio, cropped to 300×600)
Benefit line kept short (5–7 words) — the promo tab shows about 40 characters before the ellipsis

How to structure a Demand Gen creative batch

Lock the persona and product. Same persona and product across Discover, Shorts, and Gmail so the creative reads as a coherent campaign to the ranker.
Generate the three format outputs in one session.1:1 + 1.91:1 for Discover, 9:16 for Shorts, 4:5 (crop to 300×600) for Gmail. Same persona, same product, different scene compositions per format.
Ship all three formats to a single Demand Gen campaign.Google's optimization needs the full format matrix to route delivery efficiently.
Refresh weekly.Demand Gen creative fatigues faster than search — a 2–3 week refresh cadence is typical for high-spend accounts.

Demand Gen vs Performance Max: when to use which

Demand Gen and Performance Maxboth accept image + video creative, but they serve different intents. Performance Max is the shopping-signal-heavy campaign — Google routes it toward users likely to convert on a purchase. Demand Gen is upper-funnel visual discovery — it fills Discover, Shorts, and Gmail with brand-appropriate creative for audiences who are browsing, not searching.

A common mistake is running the same creative across both campaigns. Performance Max wins with product-focused imagery and shopping-feed data; Demand Gen wins with persona-first UGC-style creative. Splitting the batch by campaign intent lifts efficiency meaningfully.

Disclosure on Demand Gen creative

Google's AI-content disclosure policy applies to Demand Gen creative the same way it applies to YouTube ads. For synthetic-persona AI UGC in 2026, the recommended approach is a platform-level AI-content declaration in the ad account plus an in-text disclosure in the ad's headline or description on regulated categories. See the disclosure guidelines for the current rules.

Frequently Asked Questions

What aspect ratios does Google Demand Gen accept for AI UGC creative?

Demand Gen accepts multiple ratios per placement: 1:1 (square, min 1200×1200) and 1.91:1 (landscape, min 1200×628) for Discover feed, 9:16 vertical (min 1080×1920) for YouTube Shorts and vertical in-stream, 16:9 landscape (min 1200×628) for YouTube in-stream, and 300×600 or 300×1200 for Gmail promo tab visuals. Batches generated in ppl.studio at 4:5 crop cleanly to Gmail dimensions; the same session can output the 1:1, 1.91:1, and 9:16 formats from a single persona × product combination. Uploading only one format shrinks Google's delivery envelope — the campaign underdelivers because the ranker can't route across surfaces.

Should the same AI UGC creative run across both Demand Gen and Performance Max?

No — running identical creative across both campaigns wastes budget on both sides. Performance Max is shopping-signal-heavy and rewards product-focused imagery with strong shopping-feed data. Demand Gen is upper-funnel visual discovery and rewards persona-first UGC-style creative on Discover, Shorts, and Gmail. Split the batch by campaign intent: PMax gets product-in-scene shots optimized for shopping-tag CTR; Demand Gen gets persona-first UGC that reads native to Discover and Shorts. This split typically lifts blended ROASby 15–30% versus running the same asset library across both.

How often should Demand Gen creative be refreshed?

The 2026 benchmark for Demand Gen creative refresh is a 2–3 week cadence for high-spend accounts and a 4–6 week cadence for lower-spend accounts. Demand Gen creative fatigues faster than Search or Shopping because the placements (Discover, Shorts, Gmail) are scroll-heavy visual surfaces where the same asset stops earning attention quickly. AI UGC makes weekly refresh economically viable — a single 30-minute generation session produces a full new persona × product × format batch that can replace the fatiguing set. Teams that refresh on this cadence report CTRstaying within 10% of week-1 levels through week 6; teams refreshing monthly see CTR drop 30–40% by week 4.

Does the Gmail promo tab placement in Demand Gen actually drive results?

For DTC and e-commerce brands with an existing email audience overlap, yes — Gmail promo placements in Demand Gen consistently produce lower CPAthan Discover for retargeting and warm audiences, and CTRs are competitive with Meta paid social for lookalike audiences. The undervalued lever is the visual creative: most brands upload plain product images to Gmail placements, which look identical to every other promo card in the tab. AI UGC face-first creative (persona portrait + product close-up + short benefit copy) meaningfully outperforms product-only visuals here because the promo tab's presentation format rewards visual differentiation. The 4:5 crop from a standard ppl.studio session outputs to Gmail's 300×600 spec cleanly.

Batch-generate Demand Gen creative in a single session

ppl.studio outputs the Discover 1:1 and 1.91:1 image, the YouTube Shorts 9:16 vertical, and the Gmail 300x600 promo card — all from the same persona and product prop, in one batch. Upload your product, pick your persona, and ship a full Demand Gen creative set today.

Start free with ppl.studio

10 free photos · no credit card required

Max Zeshut

Founder of ppl.studio. Building AI tools for product marketing teams who need visual content at scale without the production overhead.