Building a long-term relationship with influencers primarily involves understanding their interests, communicating openly, and treating them as respected partners. Here are a few strategies:

1. Detailed Research: Understand their content style, interests, and audience demographics. This will allow you to choose influencers who align with your brand’s values, ensuring greater authenticity.

2. Clear Communication: Be transparent with your expectations, campaign objectives, and deliverables. This avoids misunderstandings and fosters mutual respect.

3. Negotiate Fairly: Work out compensation structures that benefit both parties. Recognition and fair payment can go a long way towards making relationships last.

4. Be Supportive: Provide resources and creative freedom for the influencers to deliver in the way they know best.

5. Consistent Interaction: Keep in touch even when there’s no ongoing campaign. This continuous engagement promotes loyalty and understanding.

Tools like Flinque or similar influencer marketing platforms, make these steps easier by offering features for efficient influencer search, effective communication, project management, and performance analytics. Each platform varies in its offerings. For instance, Flinque prides itself on providing comprehensive audience analytics, which aids in discovering influencers whose audience aligns with your target market.

Remember, platforms are tools and their effectiveness largely depends on the strategic decisions of your marketing team. Hence, consistency, authenticity, and respectful communication cannot be overlooked in the quest to build long-lasting influencer relationships.