What is Audience Expansion in LinkedIn Ads?
Audience Expansion is a campaign-level setting in LinkedIn Ads.
When enabled, LinkedIn extends your targeting to include users outside of your defined audience who share “similar characteristics” to the people you’ve chosen.
The idea is to help you discover new prospects. But in practice, expansion often makes targeting too broad, resulting in weaker relevance and lower conversion rates.
Audience Expansion is controlled at the campaign level only.
Once switched on, it applies to all targeting in that campaign.
Many LinkedIn Ads experts recommend turning it off by default to preserve targeting precision.
Why should I turn it off?
Audience Expansion frequently reduces performance instead of improving it:
Lower conversion quality. Clicks come from people with only vague similarities to your chosen audience.
Unreliable ROI. Spend gets diluted across profiles unlikely to convert, driving CPA up.
Targeting creep. Expansion can pull in irrelevant industries, job titles, or seniorities.
Loss of visibility. LinkedIn doesn’t provide detail on who’s added via expansion, so you can’t adjust targeting based on data.
How does this Improvement work?
Opteo monitors your LinkedIn campaigns and highlights whenever Audience Expansion is active.
Instead of manually checking each campaign setting, we’ll surface these campaigns straight to your Improvements list.
We also record how long it’s been on, so you’ll know if this is a recent change or something that has been quietly diluting performance for weeks.
Inside the Improvement, you can switch Audience Expansion off in a single step. This ensures your targeting stays focused on the audiences you’ve deliberately chosen - not the extra ones LinkedIn adds in the background.
When is Audience Expansion bad?
Here are common scenarios where advertisers run into trouble:
B2B with niche targeting
Example: You’re targeting IT Directors in companies with 200+ staff. Expansion may spill into junior IT roles or unrelated functions, burning budget on non-decision-makers.
Industry-specific campaigns
Example: Ads for a SaaS product aimed at healthcare providers. Expansion could show to audiences in retail or finance simply because they “engage with similar content.”
Geographically limited offers
Example: A training provider offering courses in London only. Audience Expansion may surface impressions from users across the UK or even internationally.
High-CPM environments
LinkedIn clicks are costly. Any wasted impressions from “fuzzy” lookalike audiences can erode ROI quickly.
When can Audience Expansion be helpful?
There are limited cases where this setting might add value:
Brand awareness campaigns. Reach matters more than precision.
Early-stage campaigns. If you lack first-party data, expansion can help seed audiences.
Testing budgets. For advertisers exploring market fit with flexible budgets.
If you decide it makes sense for a campaign, you can dismiss the Improvement in Opteo.