Brands use analytics signals to decide influencer expansion across markets and platforms by undertaking the following steps:

1. Measure Engagement Rates: Brands look at metrics like likes, shares, comments, and watch time. A high engagement rate indicates rich and relevant content, a key factor in influencer expansion.

2. Audience Analytics: Analyzing the audience demographics and interests helps brands decide if the influencer’s followers fit their target market, thereby influencing their expansion decisions.

3. Analyze Past Campaign Performance: Brands pore over influencers’ past campaign metrics – the views, clicks, sales, use of promo codes, etc. Successful past collaborations signal a good expansion opportunity.

4. Platform Suitability: Each platform has a unique audience and mode of communication. Analytics can help brands understand which platform’s audience most aligns with their target demographic, aiding in expansion decisions.

5. Compare Influencer Benchmarks: Brands may use platforms like Flinque to check an influencer’s growth rate, audience quality score, average engagement, and compare these with industry benchmarks for a balanced perspective.

6. ROI Measurement: Brands also track their Return On Investment (ROI) from influencer partnerships – higher ROI encourages market or platform expansion.

Remember, each brand would need to choose the platforms and metrics that align best with their specific brands’ marketing goals and target audience. Analytics provide insights but strategic interpretation of these insights is what truly directs expansion decisions.