Territory Management in a B2C environment

Territory Management in a B2C environment

We are configuring CRM for a B2C client who runs multiple e-commerce stores. For B2C i have used the standard set-up of changing 'account name' to 'not required' for Leads, Accounts, Contacts etc.

I wanted to use Territories to split our crm data based on which e-commerce store (domain) they users has come from - probably defined in the Lead Source field.

However I note that to create a territory you only have the option to apply an Account Rule, which is redundant in the B2C scenario.

Any suggestions on how else I can implement territory type of functionality related to Leads / contacts rather than accounts?