Google's new customer acquisition goal can only skip existing customers it can identify. It does that from lists you provide, a conversion tag that marks new customers, or its own auto-detection. Auto-detection only switches on if you already track Google Ads purchase conversions. So on a lead gen campaign with no customer list, 'only bid for new customers' has almost nothing to work from.
What we saw on a call
On a mentoring call, we went through a B2B SaaS's Google Search campaign. It was optimizing for sign-ups, and under customer acquisition it was set to only bid for new customers. The obvious question: had anyone uploaded a list of existing customers? Nobody on the call could say for sure. That question was really for whoever had set the campaign up.
Our point was simple: don't restrict bidding to new customers until you've told Google who your existing customers are. Otherwise you've given the campaign a rule it can't apply.
How Google tells new from existing
Google lists four ways to define existing customers, and they can be combined:
- Customer Match lists. Your own customer data, uploaded directly or through a CRM connector. Anyone not on your lists is treated as new.
- Website or app remarketing lists. Lists built from your website or app tag.
- Conversion tag. A parameter that marks each conversion as a new or existing customer. Precise, but needs developer work, and Google says it only works with Purchase conversions.
- Google auto-detection. Builds an existing-customer list from up to the last 540 days of campaign activity and tracked purchases.
The catch is in that last one. Google says auto-detection only activates if you're already tracking Google Ads purchase conversions. A SaaS optimizing for sign-ups or demo requests usually isn't, and the conversion tag route has the same Purchase-only limit. And even when purchases are tracked, Google calls auto-detection the easiest option but less comprehensive, since people clear cookies or opt out, and recommends supplementing it with Customer Match.
Lead gen is exactly where this bites
Google has two main acquisition modes. Bidding higher for new customers needs a purchase conversion goal and value-based bidding. Only bidding for new customers is the one Google recommends for lead generation and strict acquisition budgets, and it works with Maximize conversions or Target CPA.
So the mode built for lead gen is the one most likely to run without auto-detection. That makes your list the whole definition of "existing customer". Skip it, and the campaign still says new customers only. It just can't tell who isn't.
Set it up properly
- Upload your customers first. Export them from your CRM and add them as a Customer Match list, then select it as an existing customers list in the goal.
- Mind the size. Google needs at least 100 active members for a list to be used, and says lists under 1,000 may weaken results.
- Keep it current. A list from last year means this year's customers count as new. A CRM connector through Google Ads Data Manager can keep it in sync.
- Add remarketing lists too. Google recommends pairing tag-based lists with Customer Match for the best coverage.
The same list can work twice. On another call, an advertiser had added their own brand name as a negative keyword so the campaign would only bring net-new business. A customer list gets closer to what they wanted without hiding the brand from new prospects searching for it. We cover the exclusion side in stop paying to re-acquire rejected leads.
The takeaways
- 'Only bid for new customers' skips the customers Google can identify. Anyone it can't match counts as new.
- Auto-detection only activates if you track Google Ads purchase conversions. A lead gen campaign often doesn't.
- Upload a Customer Match list of existing customers before turning the goal on. At least 100 active members, ideally over 1,000.
- Keep the list in sync, and add remarketing lists alongside it.
Common questions
How does Google Ads know who is a new customer?
Google identifies existing customers from Customer Match lists you upload, website or app remarketing lists, a new customer parameter in your conversion tag, and its own auto-detection. Anyone it can't match to those sources is treated as new.
Does the new customer acquisition goal work without a customer list?
Only partly. Google auto-detection builds an existing-customer list from up to 540 days of campaign activity and tracked purchases, but it only activates if you already track Google Ads purchase conversions. Google calls it the easiest option but less comprehensive, and recommends adding Customer Match lists.
Can I use 'only bid for new customers' on a lead generation campaign?
Yes. Google recommends New Customer Only mode for strict acquisition budgets or non-purchase goals like lead generation, and it works with Maximize conversions or Target CPA. Because auto-detection and the conversion tag parameter both need purchase conversions, a lead gen campaign relies on the lists you provide to know who to exclude.
How big does my customer list need to be?
Google requires customer lists to have at least 100 active members in at least one network to be used, and says lists with fewer than 1,000 members may weaken new customer acquisition results. You can select up to 100 lists per goal.
Which campaign types support the new customer acquisition goal?
Search, Performance Max, Shopping and Demand Gen. The value-based mode, which bids higher for new customers, needs a purchase conversion goal and Target ROAS or Maximize conversion value. New Customer Only also allows Maximize conversions and Target CPA.