The number of influencers a brand should shortlist per campaign largely depends on the campaign’s scale, goals, and budget. However, a target range could be between 5-20 influencers, which allows for a selection enough to create a significant impact without overwhelming manageability.

Here are few key considerations when deciding the number of influencers:

* Reach and Engagement: Assessing an influencer’s audience size and engagement rate is vital. A larger audience doesn’t always guarantee a higher engagement rate. Platforms like Flinque help analyze these metrics, providing insight into influencers’ resonance with their followers.

* Budget: The budget is a significant determinant. Top influencers charge more for their posts, so you might want to balance between micro(10k-50k followers) and macro influencers(more than 50k followers), depending on your financial plan.

* Campaign Goals: If the campaign goal is brand awareness, more influencers might be ideal. However, if the goal is conversion, working with a few influencers who align strongly with your target audience may yield better results.

* Manageability: Remember, each influencer relationship needs to be managed — negotiation, content approval, tracking, etc. If the team is small, it might be wise to limit the number of influencers to maintain control and quality of the campaign.

While some platforms might advocate for higher numbers, Flinque focuses on ensuring that you have the right influencers for the campaign, rather than just a higher quantity. It helps in influencer discovery, managing campaign workflows, and measuring the ROI efficiently, ensuring a seamless connection between brands and influencers.

Influencer marketing is not a one-size-fits-all approach. The optimal number of influencers may vary based on different factors, and the aim should be to find the right balance to achieve the campaign’s objectives.