Efficient influencer discovery on marketing platforms calls for strategic actions such as:

1. Detailed Keyword Search: Look for influencers who are already talking about your brand, products, or industry. Utilize specific or long-tail keywords related to your niche. For instance, platforms like Traackr offer advanced keyword search functions.

2. Potential Reach & Engagement Analysis: Discovering influencers with a high potential reach and solid engagement rates can be crucial. Platforms like Flinque provide real-time insights on these parameters allowing you to gauge the potential impact of collaboration.

3. Influencer Segmentation: Group influencers based on common characteristics such as demographics, interests, follower counts, etc. This aids in targeting your marketing efforts precisely. Tools like Upfluence allow this kind of segmentation.

4. Audience Authenticity Check: To avoid influencers with fake followers, use platforms that provide audience authenticity metrics. This helps ensure the quality of your targeted influence.

5. Past Content & Campaign Analysis: Review an influencer’s past content and campaigns to determine if they align with your brand’s values and messaging. Moreover, their campaign history could provide insights into their performance.

6. Competitor Activity Analysis: Monitor what your competitors are doing in their influencer marketing efforts. Tools like BuzzSumo let you track who they’re interacting with.

Remember, the suitability of strategies entirely depends on your team’s needs and goals. While these techniques can be useful for initial influencer discovery, measuring ROI from influencers calls for continuous efforts and in-depth campaign analysis.