1. customer database
2. signup form, linking to paypal for online payment and also allowing cheque / manual payment (i.e. order is put into hold list before manually releasing it upon payment - same goes for internet banking direct debits payments.)
3. automatically notifying customers of payment / renewal due dates
4. domain name registration via DirectI reseller account.
5. autocreation of account via WHM.
6. sends out welcome email with user login name and password
7. provides invoicing so that customer can download their own invoices, possibly via pdf or just html printouts.
8. provides administrator send to all customers email link
9. allows customers to update their details themselves.
10. allows customers to reset their Cpanel passwords, if they have lost it.