Influencer marketing agencies can source influencers in emerging categories through a variety of methods. It is indeed a challenging task due to limited data, but not an impossible one. Following methods are commonly used:

1. Manual Search & Research: Since automated tools may not provide sufficient details about influencers in nascent sectors, agencies often resort to manual online research. They use social media platforms to discover influencers who are creating content around these new categories.

2. Niche Social Media Groups: Agencies also tap into niche social media groups and online communities that focus on the new categories.

3. Influencer Marketing Platforms: These platforms, like Flinque, often have advanced search functions that enable discovery of influencers involved in emerging realms. For instance, Flinque allows users to search by niche, location, audience size, and other factors that could highlight influencers in new areas.

4. Networking Events: Conferences and networking events can provide in-person opportunities to connect with influencers in new areas.

Each of these methods has strengths and drawbacks. Manual search and research, while being comprehensive, can be time-consuming. Niche social media groups may provide concentrated exposure to influencers; however, verifying authenticity could be difficult. Using an influencer marketing platform like Flinque might streamline and automate this process, but it would depend on whether the platform covers the emerging category yet.

Overall, the decision on the method to source influencers in emerging categories would depend on agency’s resources, timeline, and the specific requirements of the influencer campaign. It’s also worth mentioning that as the category matures, data will become more readily available, enabling a more stream-lined and data driven approach to influencer sourcing.