Google Demand Gen Campaigns: The Complete Guide to Replacing Discovery Ads in 2025

What Is Demand Gen (And Why Discovery Had to Die)

Let me be honest: Discovery campaigns were always a bit underwhelming. They launched in 2019 with fanfare about "reaching people where they are browsing and exploring" but in practice, they were a carousel ad format with limited placements and clunky reporting. I ran them for over a dozen clients and the results were consistently "fine." Not bad. Not great. Just fine.

Demand Gen is what Discovery should have been from day one.

Google launched Demand Gen in October 2023 and forced all Discovery campaigns to migrate by early 2024. This was not just a rename — it was a fundamental expansion of what the campaign type can do. Think of Demand Gen as Google's answer to Meta's upper-funnel ad products, designed specifically for the visual, scroll-stopping creative that drives demand before someone is actively searching.

The core difference? Discovery was limited to static images and carousels in the Discover feed and Gmail. Demand Gen adds YouTube Shorts, YouTube in-stream, and YouTube in-feed to the mix, plus entirely new features like lookalike segments and native A/B creative testing.

The Strategic Shift: "Google finally understood that not every buying journey starts with a search. Sometimes you need to create the demand before you can capture it. Demand Gen is Google admitting that Meta was right about one thing: scroll-stopping visual creative matters."

Where Your Ads Actually Show Up

Demand Gen reaches over 3 billion users across Google's visual surfaces. Here is exactly where your ads appear:

The YouTube placements are the real game-changer. Discovery never had them. YouTube Shorts alone gets over 70 billion daily views. That is an ocean of attention that Discovery campaigns could not touch. And because Demand Gen uses Google's AI to optimize placement mix automatically, your budget flows to wherever the algorithm finds the best performance signals.

One thing I have noticed across campaigns: YouTube typically eats 50-60% of the impression share, Discover gets 25-35%, and Gmail gets the remaining 10-15%. If you want to control this, Demand Gen does let you create placement-specific ad groups — a feature PMax does not offer.

Migrating from Discovery to Demand Gen

If you haven't migrated yet (or if Google auto-migrated your campaigns and you want to optimize them), here is what to know:

What Carried Over Automatically

• All your existing ad groups and targeting settings
• Historical performance data and learnings
• Conversion settings and attribution windows
• Budget and bidding settings

What You Need to Add Manually

• Video assets: Discovery only used images. Demand Gen can run video across YouTube placements. If you don't add video, you are leaving the biggest placement group on the table
• Lookalike segments: A new feature — build these from your existing customer lists
• A/B creative experiments: Take advantage of native experiment support

Migration Checklist

Audit your existing creative assets. If you only have static images, you need to create video. Even simple motion graphics or product demo clips work

Upload at least one vertical video (9:16) for YouTube Shorts and one landscape video (16:9) for in-stream

Build lookalike segments from your highest-value customer lists

Review bidding strategy. Discovery defaulted many advertisers to Target CPA. Consider switching to Maximize Conversions with a target CPA, which gives the algorithm more flexibility

Set up conversion tracking properly — Demand Gen relies heavily on conversion signals for optimization

Creative Best Practices for Demand Gen

This is where Demand Gen lives or dies. The placements are inherently visual — you are competing against Instagram reels, TikToks, and curated news feeds for attention. Your creative needs to be scroll-stopping, not just compliant.

The Asset Requirements

Demand Gen supports three ad formats within a single campaign:

• Single image ads: At least 3 landscape (1200x628) and 3 square (1200x1200) images
• Carousel ads: 2-10 cards per carousel, each with its own image, headline, and URL
• Video ads: Landscape (16:9), square (1:1), or vertical (9:16) — all three aspect ratios recommended

What Actually Works

After running Demand Gen campaigns across e-commerce, SaaS, and lead gen, here is what I have learned:

For images:

• Lifestyle imagery outperforms product-on-white by 2-3x on CTR
• Include faces when possible — human connection cuts through algorithmic feeds
• Bold, readable text overlays perform well in Discover (treat it like Instagram)
• Carousel format consistently outperforms single image on engagement

For video:

• Hook in the first 2 seconds or lose the viewer. Lead with the problem, not your logo
• Vertical video (Shorts format) typically delivers the lowest CPM due to massive inventory
• Keep videos under 30 seconds for Shorts, 15-60 seconds for in-stream
• Testimonials and UGC-style content outperform polished brand videos significantly

For copy:

• You get up to 5 headlines (40 chars) and 5 descriptions (90 chars) — use all of them
• Front-load the value proposition. "Save 40% on..." beats "Introducing our new..."
• Include social proof: "Join 50,000+ marketers" or "Rated 4.8/5"
• Test question-based headlines — they drive curiosity clicks

These are the same principles that work in Meta creative testing — visual-first platforms reward thumb-stopping creative above all else.

Audience Targeting and Lookalike Segments

Demand Gen gives you more targeting control than Performance Max, which is one of its biggest advantages.

First-Party Audiences

• Customer Match lists: Upload your CRM contacts for direct targeting or exclusions
• Website visitors: Retarget based on page visits, time on site, or specific actions
• YouTube audiences: People who watched your videos, subscribed, or engaged
• App audiences: Users who installed or took specific in-app actions

Lookalike Segments (Demand Gen Exclusive)

This is the feature that makes Demand Gen a genuine Meta competitor. You can create lookalike audiences based on any of your first-party seed audiences, with three expansion levels:

My recommendation: Start with balanced lookalikes built from your actual purchasers. Purchaser-seeded lookalikes consistently outperform broader seeds because the quality signal is stronger.

Optimized Targeting

Demand Gen includes Google's "Optimized Targeting" toggle. Leave it on for prospecting campaigns and off for retargeting campaigns. When it works, it finds pockets of demand you would never have targeted manually.

Bidding Strategies and Measurement

Bidding Options

Start with Maximize Clicks for the first 2-3 weeks to build data, then switch to Maximize Conversions once you have enough signal.

Measurement and Attribution

Demand Gen is an upper-to-mid funnel campaign type. Judging it purely on last-click conversions will make it look worse than it is:

• Data-driven attribution: Use Google's DDA model to capture assist value
• View-through conversions: Enable these — many conversions happen after someone sees your ad but converts via search later
• Brand lift studies: Available for campaigns spending $10K+/month
• Conversion lag: Give campaigns at least 2-3 weeks before judging performance

Measurement Reality Check: I have had clients try to kill Demand Gen campaigns after 5 days because "the CPA is too high." When we looked at 30-day data with proper attribution, those same campaigns had the best incremental ROAS in the account. Patience and proper attribution windows are non-negotiable.

Demand Gen vs Performance Max: When to Use Which

This is the question I get asked most. The answer: both, but for different jobs.

The ideal setup: Run Performance Max to capture bottom-funnel demand. Run Demand Gen to create top-of-funnel awareness and fill PMax's pipeline. They are complementary, not competing.

For a deeper dive on PMax strategy, check our Performance Max guide.

Your Demand Gen Launch Checklist

Before Launch:

• Conversion tracking verified and firing correctly
• At least 3 image assets per aspect ratio (landscape + square)
• At least 1 video asset (vertical for Shorts, landscape for in-stream)
• 5 headlines and 5 descriptions written and loaded
• Customer Match list uploaded (minimum 1,000 emails)
• Lookalike segment created (balanced, from purchaser list)
• Budget set to at least 15x target CPA daily

Week 1:

• Monitor impressions by placement — ensure YouTube is receiving budget
• Check creative asset performance — pause any assets rated "Low"
• Verify conversions are tracking in the campaign
• Do NOT change bidding or budget yet

Week 2-3:

• Add new creative variations based on early performance data
• Test carousels vs single image vs video in separate ad groups
• Launch A/B experiment on your top-performing audience
• Compare Demand Gen metrics with your YouTube campaigns and PMax

Week 4:

• Pull 30-day attribution data (not just last-click)
• Calculate incremental ROAS including view-through conversions
• Scale winning ad groups by 20-30%
• Build second lookalike from a different seed audience

Ready to launch your first Demand Gen campaign with AI-powered optimization? AdsMAA's platform helps you manage Demand Gen alongside your Meta and TikTok campaigns in one dashboard — with AI-driven budget allocation that automatically shifts spend to your best-performing channels.