Should tenants be deleted? What about historical reporting?

I am creating a multi-tenant SaaS app with a shared-db, shared-schema. Here is my question: What are good开发者_开发问答 policies for deleting tenants? Here are some of my thoughts...

If I delete a tenant and all its associated data:

1. I will lose my ability to report off that data
2. I will get rid of data that I don't need (a good thing, except for reporting)
3. I will free up things like subdomain names that other tenants might want

Does anyone have any best practices or suggestions for this subject?

Piet

Don't report off of production, report off of a data warehouse. Roll the warehouse over periodically into different generations, then you can purge production to match those ages.