6 Ways to Expand Your Audience Pool with Programmatic Advertising

As ad professionals, we’ve all hit that wall with audience growth.

You’re running programmatic campaigns, hitting your usual segments, but it feels like you’re just talking to the same people over and over. Expanding your reach shouldn’t mean wasting budget on random users, or guessing what might stick.  

The good news is, there are practical, low-fuss ways to grow your audience with programmatic. Below, we'll break down the strategies we’ve seen that work for fellow advertisers and publishers.  

1. Start with first-party data: Turn your biggest fans into a blueprint for new audiences

First-party data is your secret weapon here, because it’s made of people who already get your brand. Think about it: the customers who come back, the site visitors who spend time reading your content, the app users who don’t ghost you after sign-up. They can serve as a roadmap for finding more people like them.  

Here’s how to use it:

Start by picking out your “high-value” groups. Maybe it’s the shoppers who spend over $100, or the leads who actually respond to your follow-ups. Once you’ve got that group, you can use programmatic to find users with similar habits—things like what they browse, the sites they visit, or even the devices they use.  

2. Contextual targeting: Reach people when they’re already interested

Remember when we all relied on third-party cookies to target users? Well, those days are gone.

Now, contextual targeting is a better replacement. It lets you show up when someone’s actively engaging with a topic related to your brand. No more targeting someone who searched for “running shoes” six months ago; this is about catching them mid-research.  

For example, if you’re a fitness brand, you don’t just target “25–35-year-olds.” You target people reading articles about “home workouts for busy parents” or watching videos on “beginner yoga routines.” If you’re B2B, you go after people reading blogs about “small business cash flow tips” or listening to podcasts about “remote team management.”  

The key here is to keep it specific. Don’t cast a wide net with “business topics”; narrow it down to what your audience is actually talking about. And if you’re not sure where to start, platforms like GatherStar can point you to the right content spaces for your brand.  

3. Stop sleeping on underused programmatic channels

Let’s talk about display ads: They work, but they’re not the only game in town. If you’re only using display to expand your audience, you’re missing out on whole groups of users who don’t hang out there, like people streaming TV, using niche apps, or listening to podcasts.

Take CTV, for example. More and more people are ditching cable, and programmatic CTV lets you reach them while they’re watching shows or movies that align with your brand. A meal-kit brand might advertise during cooking documentaries; a B2B software brand could show up during business podcasts.  

In-app is another one. Think about the apps your audience uses daily. A finance brand might target budgeting app users; a beauty brand could go after skincare routine trackers.

4. Zero-party data: Ask your audience what they want (it’s that simple)

Zero-party data is the information people voluntarily give you, such as survey answers, quiz results, or even the preferences they share when signing up for your email. The reason it’s so powerful for audience expansion is that it’s 100% aligned with what your audience cares about.  

Let’s say you’re a skincare brand. You create a quick quiz: “What’s your skin type?” and “What’s your biggest concern?” People who answer “oily skin” and “acne” are telling you exactly what they need, and you can use programmatic to find more people who’ve shared those same preferences (either through your own quizzes or partner tools).  

The key here is to keep the questions short. No one wants to fill out a 20-question survey. A 3–5 question quiz or a simple preference check-box works.

5. Niche publishers: Don’t sleep on the small, targeted sites

Some advertisers may focus only on big, mainstream publishers for programmatic. The truth is, niche publishers, think industry blogs, local news sites, or community forums, are where you’ll find highly engaged audiences that big platforms miss.  

If you’re a healthcare brand, advertising on a small medical blog for primary care doctors will get you in front of a more relevant audience than a general health site. If you’re a B2B tech brand, a niche IT forum where developers hang out is gold.  

6. Retargeting: Win back the “almost” audiences (they count too)

Retargeting gets a bad rap for being “just for people who already know you,” but it’s actually a great way to expand your active audience. Think about it: You’ve got users who visited your site, added something to their cart, or started a form...then bailed. These people are already interested; they just need a nudge.  

Here’s how to make it work:

Don’t send the same generic ad to everyone. If someone left a cart with running shoes, show them that exact pair with a small discount. If someone read a blog post about “beginner SEO,” send them an ad for your SEO guide.  

Wrapping up: Keep it simple, focus on quality

At the end of the day, expanding your audience with programmatic isn’t about reaching as many people as possible; it’s about reaching the right people. The strategies above work because they’re rooted in trust, relevance, and not overcomplicating things.  

Ready to stop hitting that audience wall? Start small, pick one strategy (like first-party lookalikes or niche publishers) and test it. You’ll be surprised how quickly you can grow your reach without wasting budget.

If you’re looking to craft more effective, AI-driven ad experiences, start with GatherStar today. And if you want dedicated expert support to maximize your results, reach out to the GatherStar team to explore how we can help elevate your programmatic campaigns.