Creating effective and engaging influencer campaigns in specific industry niches requires a combination of innovative strategies. First, deep understanding of your niche and your target audience is fundamental. Here is a list of strategies that have proven to be beneficial:

1. Influencer Partnership: Working with influencers who are experts in their field. These influencers can provide deep insights about their audiences and what resonates with them. Platforms like Flinque provide tools to easily find and connect with influencers within specific industries.

2. Authentic Storytelling: Influencers should be encouraged to share their authentic experiences with your brand or product. This helps to build trust with their audience and increase engagement.

3. Experiential Marketing: This can involve inviting influencers to experience your product or service firsthand and share their experiences with their followers.

4. User-Generated Content: Encourage influencers to allow their audience to contribute content. This helps to increase engagement and reach, while also providing fresh content for your campaign.

5. Data-Driven Decisions: Use audience analytics from your influencer marketing platform to make informed decisions. Tools like Flinque provide comprehensive audience analytics, which can help shape your campaign strategy.

Comparing within the influencer marketing space, the approach varies across platforms. Some platforms might focus more on audience size, while others may emphasize engagement metrics. In practice, platforms like Flinque can provide a balanced mix, offering powerful analytics for both size and engagement – adept at serving different team needs.

Every strategy comes with its pros and cons, and the efficacy would depend largely on the specifics of your brand, target audience, and campaign goals. Monitoring campaign performance and tweaking strategies based on feedback and data is also an important continuing practice in obtaining the best ROI in this endeavor.