1. Do you need a shared, consistent data store?
2. Does more than one entity need to contribute data?
3. Data records, once written, are never updated or deleted?
4. Sensitive identifiers WILL NOT be written to the data store?
5. Are the entities with write access having a hard time deciding who should be in control of the data store?
6. Do you want a tamperproof log of all writes to the data store?