Google Demand Gen ROAS Benchmark 2026: The 10-20% Budget Threshold

Google Demand Gen ROAS Benchmark 2026: The 10-20% Budget Threshold

Fospha's Q4 2025 study of 25 retail and ecommerce brands found that allocating 10-20% of total Google Ads budget to Demand Gen campaigns correlates with approximately 2x ROAS compared to brands allocating under 5%. This is not a linear relationship. There is a threshold effect where minimal Demand Gen spend fails to activate the channel's multiplier on Search and Shopping. If your Google Ads budget currently puts less than 5% into Demand Gen, the benchmark suggests you are leaving conversion lift on the table.

Key takeaways

1. Brands allocating 10-20% of Google Ads budget to Demand Gen saw approximately 2x ROAS compared to brands under 5%, per Fospha Q4 2025 data from 25 retail and ecommerce brands.
2. The relationship is a threshold effect, not a gradient: moving from under 5% to 10-20% produces the lift; incremental increases above 20% show diminishing returns in the study data.
3. Demand Gen now runs on YouTube (in-stream, in-feed, Shorts), Gmail, and Discover simultaneously, making creative format diversification the primary variable after budget threshold is crossed.
4. Smart Bidding on Demand Gen campaigns requires a minimum of 30-50 conversion events per month to exit the learning phase; accounts with fewer conversions should consolidate targets before scaling budget.
5. Evaluating Demand Gen ROAS in isolation with a last-click model systematically understates its contribution; data-driven attribution with a 30-day lookback window is required for accurate benchmarking.

What Google Demand Gen is and what it replaced

Demand Gen: Google's campaign type that delivers visual ad creative (images, video, carousels) across YouTube, Gmail, and Discover through a single campaign structure. It replaced Discovery campaigns in 2024.

The key distinction from Search and Shopping: Demand Gen operates in the interruption model. Users are not actively searching; they are browsing content. This makes it a mid-to-upper funnel tool, not a last-click conversion driver, which is why its ROAS calculation requires a longer attribution window and a different benchmarking lens than Performance Max or Search.

The 10-20% threshold: what the data shows

The ICP problem this creates for Google Ads teams managing multi-campaign budgets: Demand Gen is frequently treated as an experimental line item, allocated 2-4% of total Google budget to test it, which is exactly the allocation range the Fospha study identifies as sub-threshold.

By the "Demand Gen allocation threshold" benchmark, Fospha's Q4 2025 study of 25 retail and ecommerce brands found the following pattern: brands allocating under 5% of Google budget to Demand Gen saw no statistically meaningful ROAS lift from the channel. Brands in the 10-20% band saw approximately 2x ROAS compared to the under-5% cohort. The study controlled for vertical (retail/ecommerce) and account scale, making the benchmark applicable to comparable brands evaluating channel mix decisions.

The mechanism: Demand Gen in the 10-20% range generates enough upper-funnel impression volume to feed the remarketing and audience pools that Search and Shopping bidding algorithms use. At under-5% spend, that pool is too thin to produce measurable lift on downstream conversion channels. The 10-20% band is the minimum viable investment to activate the multiplier effect, not just the Demand Gen channel in isolation.

Prooflytics flags accounts where Demand Gen allocation falls below 5% of total Google budget as a potential optimization opportunity, surfacing the reallocation case in the daily briefing when the account has sufficient historical data to benchmark.

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01. How to calculate your current allocation

Step 1: Pull last 30 days of spend by campaign type from Google Ads. Use the Campaigns tab with the segment set to "Campaign type".

Step 2: Sum all Demand Gen campaign spend. Divide by total Google Ads spend across all types. Multiply by 100 for the percentage.

Step 3: Compare against the 10-20% threshold. Three scenarios:

Under 5% allocation: Sub-threshold. The channel is unlikely to show meaningful ROAS lift regardless of creative quality. Evaluate whether to scale to 10% or pause and reallocate.

5-10% allocation: Approaching threshold. Monitor ROAS trend for 30-day periods. If ROAS is trending up with volume increase, continue scaling toward 10%. If flat, audit creative mix and audience targeting before adding budget.

10-20% allocation: Benchmark zone. Evaluate actual ROAS against account benchmarks. If below 1.5x on a 7-day window, prioritize creative refresh and audience exclusions over further budget increase.

02. Creative format requirements at the threshold

Demand Gen at 10-20% budget allocation requires creative depth to avoid audience saturation. The campaign serves across YouTube in-stream, YouTube in-feed, YouTube Shorts, Gmail, and Discover. Each format has different aspect ratios and duration limits.

Minimum viable creative set for a brand entering the 10-20% threshold:

• 3-5 image creatives (1.91:1, 1:1, and 4:5 aspect ratios)
• 1-2 short-form video assets (under 30 seconds, ideally under 15)
• At least one carousel format for product-focused accounts

Audience targeting at this budget range should layer custom intent audiences (built from your Google Search query terms), remarketing lists (site visitors, video viewers), and Google's similar audiences for reach expansion. Running only broad Google audiences without custom layers is the most common reason Demand Gen underperforms at the 10-20% threshold.

03. Attribution: the measurement problem

Demand Gen ROAS is systematically underreported in last-click models. A user who sees a Demand Gen ad on YouTube, leaves, and converts via a branded Search three days later will attribute 100% of the ROAS to the branded Search campaign under last-click. Demand Gen's actual contribution is invisible.

The practical fix: switch Demand Gen campaign reporting to data-driven attribution (DDA) in Google Ads, and extend your lookback window to at least 30 days. If DDA is unavailable due to insufficient conversion volume, use position-based attribution as an interim step. Never evaluate Demand Gen ROAS in isolation against a last-click model; the understatement will consistently argue against budget allocation even when the channel is performing.

What to watch

• Demand Gen ROAS below 1.5x on a 7-day window with frequency above 4.0: audience saturation is likely. Expand targeting or refresh creative before adding budget.
• Allocation above 25% of total Google budget without ROAS improvement: diminishing returns zone per the Fospha threshold model. Evaluate whether funds are better deployed in Search or Shopping.
• Learning phase active with fewer than 30 conversions per month: Smart Bidding cannot optimize effectively. Consolidate conversion actions or lower target ROAS to exit learning faster.
• Brand Search impressions increasing as Demand Gen budget scales: positive signal; the channel is building demand that Search is capturing downstream.
• View-through conversion rate below 0.5%: creative is not driving intent. Audit message-market fit before scaling budget further.

Bottom line

• The 10-20% Google Ads budget allocation to Demand Gen is a verified threshold for ROAS lift in retail and ecommerce: below 5% produces no meaningful multiplier effect per the Fospha Q4 2025 benchmark.
• Creative depth, attribution model, and Smart Bidding conversion volume are the three variables that determine whether you reach the 2x ROAS potential within that threshold.
• Evaluate Demand Gen performance with data-driven attribution and a 30-day lookback window; last-click models systematically underreport its contribution to branded Search conversions.
• See Google Ads marketing analytics for how to connect Google Ads data to the daily briefing and track Demand Gen allocation trends automatically.
• You can read independent reviews of Prooflytics on G2 and compare it against other marketing analytics platforms.