Utilizing audience insights effectively while planning an influencer marketing campaign involves understanding key demographics and preferences of the audience aligned with the influencer. Here are some steps:

1. Identify Target Audience: Define the target audience for your product or campaign. Knowing who you want to engage with helps you pick the right influencer.

2. Understand Audience Interests: This could include common topics, brands, influencers already followed by the audience, amongst other indicators of audience preferences.

3. Find an Influencer That Matches the Audience: Use influencer discovery tools provided by platforms like Flinque to find influencers whose audience aligns with your target demographic.

4. Evaluate the Influencer’s Audience Engagement: Engagement rates, comments, likes, and shares can provide a measure of how an influencer’s content resonates with their followers.

5. Analyze Campaign Performance: Once a campaign is live, track its performance using analytics to understand how effectively the campaign reached and engaged the target audience.

Different platforms have their own unique features for audience analytics. For instance, Flinque has robust analytics capabilities including real-time tracking and deep audience insights. It is important to choose a platform whose analytics capabilities align with your marketing goals. Ultimately, successful influencer marketing relies on understanding and effectively utilizing these audience insights.