If you're advertising online and not leveraging lookalike audiences, you're missing out on one of the most powerful ways to scale your campaigns. And if you're only using email addresses to build those audiences, you're not getting the full picture.
Enter: consumer phone data—a highly underutilized asset for building precise, profitable lookalike audiences.
In this blog, we'll show you how to build high-performing lookalike audiences using consumer phone numbers, where to source the data, how to upload it to platforms like Facebook and Google, and how companies across industries are using this strategy to multiply their results.
🔍 What Is a Lookalike Audience?
A lookalike audience is a group of people who are algorithmically similar to your existing customers or leads. Platforms like Facebook, Google, and even TikTok allow you to upload a “seed list” of known contacts, then automatically build an audience of new people who match similar behavioral and demographic traits.
These audiences are ideal for:
- Prospecting new customers
- Expanding campaign reach beyond current lists
- Improving ROAS (return on ad spend)
- Scaling without sacrificing targeting precision
And while many marketers use email addresses to build these lists, phone numbers often result in better match rates—especially in mobile-first environments.
📱 Why Use Consumer Phone Data?
In today’s mobile-centric world, consumer phone numbers—especially cell numbers—are tied more closely to digital identities than email addresses.
Here’s why using phone numbers can outperform emails:
- Higher match rates on platforms like Facebook (people often register with their mobile number)
- Stronger identity linkage for mobile ad networks and geofencing platforms
- Better attribution for mobile-first campaigns
- Many people have multiple email addresses but only one mobile number
If you're running paid ads and your audience match rates are low, the problem might not be your list—it might be your data type.
🧠 Where to Get the Right Phone Data
This is where list quality makes all the difference.
At Gemstone Data, we provide verified consumer cell phone lists enriched with demographics like:
- Age and income
- Homeownership status
- Interests and lifestyle segments
- Geography (down to ZIP or radius targeting)
- Product intent signals (e.g., Medicare, solar, insurance)
You can use this data to create both:
- Custom audiences for direct targeting
- Lookalike audiences to scale campaigns beyond your core list
🧰 How to Build a Lookalike Audience Using Phone Data
Here’s a step-by-step guide using Meta (Facebook/Instagram) as the example, though the process is similar on Google, TikTok, and other platforms.
Step 1: Format Your Phone List Correctly
Make sure your file:
- Is a CSV or TXT file
- Contains only the “Phone Number” column (no headers or extra fields)
Gemstone Data can deliver lists in the exact format you need—just ask.
Step 2: Upload to Facebook Business Manager
- Go to Audiences in Meta Business Manager
- Click Create Audience > Custom Audience
- Select Customer List
- Choose “No value” upload if you're not including LTV
- Upload your file and choose “Phone Number” as the identifier
- Name your audience clearly (e.g., Gemstone Cell List - Homeowners 35–55)
Facebook will hash the data and match it to user profiles. You’ll usually get a match rate within a few hours.
Step 3: Create a Lookalike Audience from Your Upload
Once your custom audience is built:
- Click Create Audience > Lookalike Audience
- Choose the source audience you just created
- Choose the location (U.S., state, or region)
- Select the audience size:
- 1% = Closest match, smallest size (~2M in the U.S.)
- 2–5% = Larger reach, slightly less precision
- Name and save the audience
BOOM—your lookalike audience is ready to go.
🧪 Real-World Use Case: Home Services Company
Let’s say you’re a home improvement company targeting homeowners in specific ZIP codes.
You get a list from Gemstone Data of:
- Homeowners age 35–65
- Cell phone numbers
- Incomes of $75K+
- Located within 10 miles of your service area
You upload the list to Meta, create a custom audience, and then build a 1% lookalike.
Result: You now have a brand-new pool of thousands of highly qualified, similar homeowners to run ads to—without having to build a list from scratch.
Companies using this method often see:
- Higher CTRs
- Lower CPLs
- Better-qualified leads
- Increased ad efficiency
🔄 Bonus Tip: Combine Phone Data with Other Channels
Phone data doesn’t just help with lookalike audiences. You can also:
- Run geofence ads to the same mobile devices
- Use the list for cold SMS (where compliant) or telemarketing follow-up
- Overlay your email campaigns for multichannel visibility
In short, one list can power three to five marketing channels—if you know how to use it.
🔐 Is It Compliant to Use Phone Numbers for Lookalikes?
Yes—if the data is sourced responsibly. Facebook and Google allow phone number uploads for audience targeting as long as:
- You have legitimate access to the data
- It complies with the terms of your data provider
- You're not using it for sensitive categories (e.g., health without consent)
At Gemstone Data, we work with clients to ensure:
- Clean, legal usage of third-party data
- Proper formatting and compliance support
- Transparent privacy practices
🚀 Final Thoughts
If you’re running paid campaigns and only using emails for your custom audiences, you’re leaving performance on the table. Consumer phone data, especially mobile numbers, gives you better match rates, deeper identity linkage, and access to more scalable lookalike audiences.
With the right list and strategy, your lookalike audience becomes more than a "guess"—it becomes a growth engine.
✅ Need a Phone List That Converts?
Gemstone Data offers:
- Verified cell phone data
- Demographic targeting and filters
- Support for Facebook, Google, and programmatic platforms
- Real-time access through our data portal
👉 Contact us today to get started building lookalike audiences that perform.