How to Optimise
Towards New Customers
in Google Ads
Google's algorithm optimises towards the easiest sale, not the most valuable one. Left to its own devices, it will quietly spend your budget re-buying customers you already had.
Why this matters
Smart bidding is built to find the path of least resistance. The cheapest conversions in any account are existing customers and brand demand - people who were always going to buy. So that's where Google points your money first. The in-platform numbers look fantastic, and the business doesn't grow.
If new customer acquisition is the goal - and for most D2C brands it's the only number that actually moves the business forward - you have to actively steer the algorithm away from the easy wins. None of this happens by default. Every lever below is about overriding Google's instinct and feeding it the right signal about who you actually want more of.
How to optimise towards new customers
Customer Match and first-party data
Upload your Customer Match lists, and not to target those people. You upload your existing customers so the algorithm has a high-quality, first-party picture of who actually buys from you, then goes and finds new people who look like them.
It's the strongest signal you can hand Google - partnered in with any GA4 audiences you layer in over the top too. Your own purchase data will always out-perform Google's off-the-shelf in-market and affinity segments, because it's built on people who have already paid you, not people Google thinks might be interested.
The goal here isn't to get Google to target them, it's to help them understand your target audience better.
Negative bid adjustments on existing customers
The same lists do a second job. In your generic (non-brand) campaigns, apply negative bid adjustments to your first-party customer lists or your GA4 audiences of existing customers.
When an existing customer searches a generic term, you don't want to pay full "new customer" prospecting prices to put an ad in front of someone who already knows you and would likely have come back anyway. Downweighting/excluding those audiences keeps your generic new customer budget pointed at genuinely cold, new people, which is the entire job of a prospecting campaign.
If existing customers are back in the market searching for the types of products you sell but don't search for your brand term - they're not loyal to you. It's best to create a duplicate generic campaign targeting the same keywords but only targeting those existing customers at a higher tROAS. This enables you to capture new & repeat customers all via non-brand.
Brand term and PMax exclusions
Add your brand terms as negatives across all your non-brand campaigns. Otherwise Google inflates your generic prospecting with brand searches - people who were going to convert anyway - and trains the algorithm on the easy wins you don't want it chasing.
Do the same for PMax: put brand lists and exclusions in place so it doesn't cannibalise your branded Search and Shopping. Let your branded campaigns do the brand job. Let non-brand find new customers.
Cold ROAS targets
New customers cost more to acquire than repeat buyers - that's the whole point of acquisition. So if you hold your prospecting campaigns to your blended or breakeven ROAS, the algorithm will read that target as "this is too expensive" and starve them, retreating to cheap retargeting and brand.
Set deliberately cold ROAS targets on prospecting. Go low - somewhere between 0 and 300% - to give the algorithm permission to spend on the harder, more expensive first purchase. You then judge those campaigns on NCAC and new customer volume, not on the in-platform ROAS, which will always look worse than your warm activity. That's a different number to your breakeven ROAS.
New customer conversion tags
Set up a conversion action that only fires when the customer is genuinely new, and route it through your CDP to confirm new versus repeat before it counts. Then feed that verified new-customer conversion back to Google as your optimisation event, so the algorithm is optimising towards real new customers rather than its own guess.
Google's native new-versus-returning distinction is only an estimate - limited by consent banners, parameter stripping and successive iOS updates. Optimise towards Google's number and you're optimising towards noise. Optimise towards a CDP-verified new-customer event and you're optimising towards the thing that actually grows the business.
The pattern underneath all of this
Every lever here comes back to the same idea. Google optimises for the easiest sale; growth comes from the hardest one. So you override the defaults, you feed the algorithm clean first-party signal about who you want more of, and you measure on verified new customers rather than the in-platform numbers built to flatter the account.
Steer it, or it steers itself - straight back to the customers you already had.
Further reading
My step-by-step process to uncover the real account problems
The foundational checks I run when dropping into any Google Ads account unseen - real problems and growth opportunities surfaced in under 20 minutes.
New customer acquisition is stalling - check these 5 things today
New customer volume flat or declining? Five diagnostic checks to identify exactly what's causing the stall in your Google Ads account.
Why your prospecting budget is being spent on retargeting
The hidden way Google Ads silently reallocates your cold audience spend towards warm retargeting audiences - and what to do about it.
Scaling Google Ads might be the wrong move for growth
Scaling the wrong channel doesn't just plateau - it actively shrinks your new customer pool. Whether a channel generates demand or captures it changes where your next pound should go.