Google Ads · Bidding
Value-based bidding tells Google what each conversion is worth so Target ROAS and Maximize Conversion Value can chase revenue instead of volume. Google's published entry bar is low. The bar at which it actually works is higher, and the two numbers we share below, one from the documentation and one from a Google event that is not in the documentation, explain most of the failures we see.
Under value-based bidding you assign a monetary value to each conversion, and Smart Bidding optimises toward total value at your efficiency target rather than toward conversion count. Google's documentation states that conversions must carry a value greater than zero to be eligible at all. That sentence matters more than it looks: if every conversion you upload carries the same value, there is no value signal to optimise, and Target ROAS behaves exactly like Target CPA with extra steps. Variation in value is the entire point.
Assigning $100 to every form fill treats an enterprise demo request and a whitepaper download as equals. The algorithm optimises the average and buys the cheap one.
A $10,000 sale at 10% margin is worth less than a $5,000 sale at 60% margin. Bid to top-line revenue and Google over-indexes on low-margin deals. We bid to gross profit, and it is the reason efficiency holds as spend scales: the platform bids lower on low-value buyers and harder on high-value ones.
Valuing on first contract alone undervalues customers who retain. Where retention data exists, it belongs in the number.
This one is harsher than a lag. Google retains the click identifier for 90 days, so a conversion uploaded after that window does not import at all. It is not a late signal. It is no signal.
Google's documentation sets the minimum for Target ROAS at 15 conversions in 30 days for Search and Shopping campaigns. Other campaign types differ: Display needs 15 across all campaigns combined, Video Action needs 30, Demand Gen needs 50 in 35 days, and App campaigns need 300. Those are the floors at which the strategy will run.
At an invite-only Google event in Toronto in November 2025, Google representatives shared a different figure that does not appear in the published documentation: roughly 50 conversions per 30 days, landing within a 7-day conversion window from the click, is what the system needs to optimise with stability. Our account experience matches the unofficial number, not the published one. Between 15 and 50, bidding runs but fluctuates; below 15 it stalls.
The 7-day window detail carries a consequence most advertisers never work out. A business whose sales close 30 or 60 days after the click structurally cannot produce 50 conversions a month that land within 7 days of the click, no matter its volume. Bidding on closed-won data in a long-cycle funnel does not merely give the algorithm slow feedback. It fails to produce the signal density Smart Bidding needs at all.
The threshold math above dictates the answer. Form fills have the volume but carry no quality signal unless you score them dynamically. Closed deals carry perfect signal but arrive too late and too thin for long cycles. The stage that clears both bars for most lead generation is the qualified lead or created opportunity: it lands within days of the click, correlates with revenue, and arrives in enough volume to feed the system.
Short-cycle businesses are the exception. A home-services funnel that books within 48 hours can and should bid on the closed transaction. Long-cycle B2B assigns proxy values by stage and reconciles actual revenue upstream. Either way the value flows in through offline conversion import against the stored click identifier, inside the 90-day window.
How offline conversion import works → · Capturing the click identifier →
At high spend, lead volume outruns the sales floor. Response times slip, close rates fall, and the algorithm trains on degraded conversion rates that were caused by your operations, not by traffic quality. The account looks like it broke. The pipeline did.
Weekly CSV uploads that were fine at $30K cannot feed millions of auction signals. The sync moves to daily or real-time via API, and API rate limits and overwritten CRM fields become bidding problems, not IT problems.
Core high-intent terms exhaust. Spend spills into broad match and Performance Max, and the bid system starts overbidding micro-audiences to hit its ROAS target, which quietly drives acquisition cost up while the target still reads green.
Fake leads that pass validation teach Google to bid on lookalikes of spam. At scale this needs CRM-invalidated lead adjustments flowing back, not just click protection at the edge.
Value-based bidding assigns a monetary value to each conversion so Smart Bidding strategies, Target ROAS and Maximize Conversion Value, optimise toward total revenue at your efficiency target instead of toward conversion count. Conversions must carry a value greater than zero to be eligible, and the values need to vary, because identical values leave nothing to optimise.
Google's published minimum for Target ROAS is 15 conversions in 30 days for Search and Shopping, with different floors for other campaign types. Guidance shared by Google representatives at an invite-only event in Toronto in November 2025, not found in published documentation, put the practical number at about 50 conversions per 30 days landing within a 7-day window of the click. Our account experience matches the higher figure.
For most lead generation, the qualified lead or created opportunity stage: it arrives within days of the click, correlates with revenue, and carries enough volume for the algorithm. Closed-won values are ideal only when the sale closes fast; in long cycles they cannot land inside the signal window in sufficient volume. Short-cycle businesses like home services should bid on the closed transaction directly.
Gross profit. Bidding to top-line revenue makes the platform favour large low-margin deals over smaller high-margin ones. Bidding to profit holds efficiency as spend scales, because the system bids lower on low-value buyers and more aggressively on high-value ones.
Almost always because every uploaded conversion carried the same value. With no variation in value there is no value signal, and the strategy degenerates into optimising conversion count. Fix the value assignment before touching the target.
Platform claims on this page are drawn from Google's documentation: About Target ROAS bidding, About Maximize conversion value bidding, About Smart Bidding using value-based bidding, and About Target CPA bidding. The 50-conversion guidance is unofficial, firsthand, and labelled as such above.
Google also offers conversion value rules, static multipliers by location or audience for accounts that cannot send real values. We rarely use them, and the reasons are worth understanding before you do.
Most accounts do not fail value-based bidding on setup. They fail on volume: no single campaign clears the conversion minimums above. Pooling Search campaigns under one portfolio combines their conversion learnings, so the thresholds become reachable together.
Next Step
If you spend $30,000 or more per month and every conversion you upload carries the same value, your Target ROAS is running blind. We build the value pipeline it needs. Let's talk.
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