Use case 1: Crypto is its own ecosystem, ICO's, exchanges
Use case 2: Trust concern between multiple parties (implementations don't work since the malicious party has benefit to stop it)
Use case 3: Transparency for legal compliance (potential if regulatory adoption)
Use case 4: Supply chain (blockchain doesn't actually secure the underlying asset, it simply records the transition, items can still be forged)
Use case 5: Co-operation (Repo, International Clearing) - I'm focusing my attention here
Use case 6: Distributed computing (doesn't need blockchain)