TLDR: Third-party cookies are disappearing and with them a lot of the targeting precision PPC has relied on. This guide walks you through exactly how to collect, connect, and activate first-party data in Google Ads, step by step, so your campaigns keep performing as tracking changes
Third-party cookies have been on the way out for years, but the pace of change is accelerating. Between privacy regulation, browser restrictions, and Google’s own evolving stance on tracking, the data infrastructure that powered PPC campaigns for the past decade is being dismantled piece by piece.
The good news? First-party data, information you collect directly from your own customers, is more powerful and more accessible than ever. The brands that get this right now will have a significant advantage. Here’s how to build your strategy from the ground up.
Step 1: Audit what first-party data you already have
Before building anything new, take stock of what you already have. Most brands are sitting on more usable data than they realise, the challenge is knowing where it is and whether it’s clean enough to use.
Run through this audit checklist:
- CRM contacts – how many records do you have? What fields are populated (email, phone, address)?
- Email lists – are these segmented? When were they last cleaned?
- Purchase history – do you have transactional data tied to individual customers?
- Loyalty programme members – high-value segment, often with rich profile data.
- On-site behavioural data – what are you capturing via GA4, heatmaps, or session recording tools?
For each data source, note the format it lives in, the approximate volume, and the last time it was updated. A small, clean list of 5,000 engaged customers will outperform a bloated, outdated list of 50,000 every time.
Step 2: Connect your CRM to Google Ads via Customer Match
Customer Match lets you upload your own customer data to Google Ads and use it to target or exclude specific users across Search, Shopping, YouTube, and Display. Here’s how to set it up correctly.
Formatting your list:
- Google accepts hashed emails (SHA-256), phone numbers, and physical addresses.
- Export your list as a CSV with the appropriate column headers (email, phone, first_name, last_name, country, zip).
- Hash email addresses and phone numbers before upload – Google provides guidance on formatting in the Help Centre.
- You need a minimum of 1,000 records to create a valid audience, but you’ll need at least 1,000 active users for the list to serve.
Uploading in Google Ads
Go to Tools & Settings > Shared Library > Audience Manager > Your Data Segments > click the blue + button > Customer List. Follow the prompts to upload your CSV.
A match rate above 30% is a reasonable benchmark. Below that, check your data formatting. For ongoing syncing, both Salesforce and HubSpot have native Google Ads connectors that automatically push updated contact lists, worth setting up if your CRM is either of these platforms.
Step 3: Set up Enhanced Conversions
Enhanced Conversions improve attribution by sending hashed first-party data at the point of conversion, allowing Google to match that conversion to a signed-in user even when cookies are blocked. This is one of the highest-impact changes you can make right now.
There are two setup methods:
Via Google Tag Manager (recommended for most) [h3]
- In GTM, open your Google Ads Conversion Tag.
- Enable Enhanced Conversions and select ‘Automatic’ collection, or manually map your data layer variables to fields like email, phone, and name.
- Capture data that users have entered on your confirmation or thank-you page.
- Preview and publish.
Via Google Ads Tag (for developers)
- Pass enhanced conversion data directly via the gtag.js event snippet using the user_data object, including email_address, phone_number, and address fields. Google will hash the data automatically.
- Once live, you’ll see an Enhanced Conversions column appear in your Google Ads reports showing the uplift in attributed conversions. Allow a few weeks for statistically meaningful data to accumulate.
Step 4: Implement Consent Mode v2 correctly
If you’re advertising to users in the UK or EU, Consent Mode v2 is not optional. It’s required for compliance and directly affects your ability to use Google’s measurement tools. Many advertisers have partially implemented it but are missing the two new parameters introduced in v2.
Basic vs Advanced Consent Mode
Basic mode blocks all Google tags until consent is given. Advanced mode allows tags to fire in a limited, cookieless state, enabling Google to model conversions using aggregated data. Advanced mode provides significantly better measurement and is worth implementing if your development resource allows.
The v2 parameters you might be missing [h3]
- ad_user_data – controls whether user data can be sent to Google for advertising purposes.
- ad_personalization – controls whether data can be used for personalised ads (including remarketing).
How to check your setup in GTM [h3]
- Install the Google Tag Assistant Chrome extension.
- Browse to your site, open Tag Assistant, and trigger a consent denial.
- Check that both ad_user_data and ad_personalization are set to ‘denied’ when the user declines.
- If they’re not appearing at all, you’re likely running v1 only and need to update your Consent Mode configuration in GTM.
Step 5: Build a first-party data collection programme [h2]
Activating existing data is only half the job. The other half is building a sustainable programme for collecting more of it. Here are the most effective tactics and what to expect from each.
- Post-purchase email capture: Ask customers to create an account or join a mailing list at checkout. Highest-intent moment. Useful within days for suppression audiences.
- Loyalty programme sign-ups: Incentivise sign-ups with discounts or early access. Yields rich, ongoing data. Takes 4–8 weeks to build meaningful volume.
- Gated content: Whitepapers, guides, or tools in exchange for an email address. Best for B2B or considered-purchase categories.
- On-site quiz or configurator tools: High engagement, captures declared preferences. Data is immediately usable for personalisation and audience segmentation.
- Preference centres: Let users tell you what they’re interested in. Improves email relevance and creates useful segmentation signals for Google Ads audiences.
Think of this as an ongoing programme, not a one-off project. The more consistently you collect and clean data, the more powerful your Google Ads targeting becomes over time.
Step 6: Activate your data in campaigns
Once your data is flowing into Google Ads, here’s how to put it to work across your campaigns.
- Remarketing with Customer Match audiences: Apply your customer lists to Search and Shopping campaigns to re-engage existing customers. Find this under Audiences in the campaign or ad group settings.
- Audience layering and bid adjustments: Overlay Customer Match audiences on top of your existing targeting and apply bid adjustments. Bid higher for high-value customer segments like lapsed buyers or loyalty members.
- Suppression from acquisition campaigns: Exclude recent purchasers from your new customer acquisition campaigns to avoid wasting budget. Add your purchaser list as an excluded audience at campaign level.
- Smart Bidding signal enhancement: Customer Match audiences fed into Smart Bidding campaigns give the algorithm additional signals to optimise towards. This is one of the most impactful and underused applications.
Step 7: Measure whether it’s improving performance
First-party data is only valuable if you can prove it’s making a difference. Here’s what to track.
- Customer Match rate trends: Monitor in Audience Manager. A declining match rate usually indicates data quality issues, stale emails or formatting problems. Aim to refresh your lists monthly.
- Conversion rate by audience segment: Compare conversion rates for Customer Match audiences versus your standard targeting. A meaningful uplift validates the strategy.
- Enhanced Conversions uplift report: Find this in Google Ads under Measurement > Conversions > Enhanced Conversions. It shows the additional conversions attributed through Enhanced Conversions that would otherwise have been missed.
If results are underwhelming, start with match rates and data quality before questioning the strategy itself. Poor match rates are the most common cause of underperformance, and they’refixable.
Conclusion
First-party data is a better foundation for PPC than third-party tracking ever was. The brands investing in it now will be better targeted, better measured, and more resilient to whatever changes come next.
If you’d like support implementing any part of this, from Enhanced Conversions setup to a full CRM integration, our PPC and Data Analytics teams are here to help. Get in touch with the ASK BOSCO team to find out more.
