Expand Your Targeting With Audience Lookalike Expansion

Illustrative graphic of a shopping cart reaching many users

For many advertisers, the most important ad targeting asset they have is their own 1st-party audience data. This data is exclusive, unique to the advertiser, highly valued, and shows the richest signals of purchase intent. This proprietary data can consist of offline CRM and transactional data such as emails, IP addresses, device IDs and phone numbers. 

The only limitation to solely relying on customer data for your campaigns is scalability. Although your 1st-party data can be very useful when it comes to re-engaging with existing prospects and customers, you won’t be able to find net-new prospects to introduce them into your marketing funnel. This is where my favourite StackAdapt feature, Audience Lookalike Expansion, comes into play.

What is Audience Lookalike Expansion

Audience Lookalike Expansion allows you to extend your audience reach by finding users who mimic the online behaviour of those you’ve targeted through your StackAdapt Custom Segments or 1st-party data—giving your campaign more scale. Marketers no longer need to specify who they want to advertise to—our technology will do all the heavy lifting, uncovering pockets of users who are similar to customers you’ve already seen success with.

Illustrative graphic of CRM audience and StackAdapt's algorithm showing results for Extended Audience

How to Create an Expansion List

When creating an expansion audience from your 1st-party data, attributes similar to those in your CRM list are identified and an audience is formed with that data. Creating an expansion list on a StackAdapt Custom Segment or Interests & Intent segment works the same way; our algorithm identifies the online behaviour of users within those segments, then looks for audiences that have similar habits.

The recommended source audience size is at least 1,000 matched active users, and the more people in the seed audience, the better. The quality of the source audience is very important—a 1st-party CRM list made up of your most loyal customers will perform more effectively than an audience of people who signed up for your marketing email list.

When To Use Audience Lookalike Expansion

This targeting strategy can be used at every stage of the buyer’s journey, especially when your campaigns need a boost in scale. Below are a few examples.

E-commerce Past Purchasers

For businesses that have a backlog of purchases and customers, they can take their CRM purchase data and use it as a seed audience for campaigns with the goal to increase online sales. If your brand offers multiple, diversified product lines targeted at different buyer personas, ensure that your CRM list upload contains audience members interested in the product your campaign will promote.

B2B Location-Based Audiences

Suppose a B2B advertiser creates a Custom Segment to collect users who attend a B2B conference in a specific location within a certain period of time. In this case, Audience Lookalike Expansion can be used to expand on this location-based segment by targeting people who are similar to those conference attendees.

Expand Off of a Negative Segment

Advertisers who want to reach only net-new audiences can upload their CRM list as a negative segment and turn on Audience Lookalike Expansion. This tactic allows you to exclude people who have historically converted and ensure spend goes towards building new leads similar to the seed audience.

Audience Lookalike Expansion vs Lookalike Audiences

Lookalike Audiences use visitors that viewed a page as the seed audience for ad targeting. They are pixel based, meaning you need to wait for an average of 4,000 pixel fires before a lookalike can begin to be built. The pixels fire during specified events, such as a site or cart visit, conversion or sale.

Whereas, Audience Lookalike Expansion uses 1st-party data or Custom Segments as the seed audience, it can be leveraged as long as there are 1,000 unique users—no advance pixel implementation required.

Consider Audience Lookalike Expansion For Your Campaign

Not only can Audience Lookalike Expansion help with scale and reach, but it can also increase your conversions up to 2x. Our clients have experienced increases in conversions, lower eCPA, reduction in the CPC and increases in CTR just from using Audience Lookalike Expansion within their campaigns.

Illustrative graphic of a CRM audience seeing an ad and then being retargetted with another ad

In one StackAdapt conversion campaign, where 40% of the conversions came from users within the CRM list, Audience Lookalike Expansion increased their conversions by 1.5x. So, if this campaign just ran on the CRM audience, they likely wouldn’t have scaled, they wouldn’t have gotten the other 60% of their conversions, and they would have had 1/3 the CTR and a much higher eCPC.

Every brand needs to continue growing and reaching new customers to achieve success. Audience Lookalike Expansion is an excellent tactic to find those new audiences that look just like your ideal buyer—making it one of my favourite StackAdapt features.

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Kaitlin Forbes
Kaitlin Forbes

Senior Director of Product Marketing


Kaitlin partners with various stakeholders to determine product messaging, positioning, sales enablement, and go-to-market strategy. With 10+ years in product marketing, Kaitlin has worked on various forms of SaaS products including programmatic and CRM.