To determine whether your influencer marketing campaign is reaching your intended target demographics, you can:

1. Engage Influencer Marketing Platforms: Tools like Flinque provide powerful audience analytics functionalities. With these, you can deeply understand the demographics of the influencer’s followers and ensure they align with your target audience. Information may include follower age, location, gender, interests, and engagement level.

2. Track engagement metrics: Likes, comments, and shares are prime indicators of audience interest. Analyzing these can help understand what content resonates with your target demographics and adjust accordingly.

3. Monitor website traffic and conversions: Integrating your campaign with website analytics tools will provide data about the influencer’s ability to drive traffic and convert leads.

4. Carry out periodic surveys: Periodic surveys can provide qualitative insights into your campaign’s effectiveness and whether it’s reaching the right demographics.

Comparatively, other platforms, such as Simply Measured or Klear, also offer detailed analytics and tracking, but the appropriateness may depend on your specific requirements and budget.

With Flinque, campaign performance tracking is part of its workflow. This allows brands and agencies to measure key metrics about influencer impact and alignments with target demographics.

Remember, ROI measurement should not only focus on direct, immediate sales. Considerations should include factors such as brand awareness and perception changes, as these long-term changes can have significant impact on brand performance and reach to the desired demographic. Always align your measurements with your business and marketing objectives for complete performance picture.

Tools and workflows can assist, but having a solid understanding of your audience and regular review of your strategy significantly contribute to the success of your influencer marketing campaign.