Hi - I have a strip center property where the lease says that if I manage the utilities, I can add a percentage to the bill as a management fee.

I'm wondering:

1. Is this common?  Do you have something similar in your own leases (whether you are a landlord or tenant)?

2. How do landlords use this clause?  Like my tenants are just directly billed by the utilities available here (water, electricity, gas).  What is the value-add I'd really be providing to justify a fee?