Office Building Signage: Can you get income from it?

[Henri Meli]

I'm curious if anyone who owns a commercial office building has strategies to get additional income via building signage.  

I own an office building that is really well situated (high traffic area) and currently have a signage from a Local Bank, who is one of my tenants. Their lease is coming up next year and I want to start discussion on an extension. The signage is on top of the building facade facing the main traffic area and is the only one on the building. The tenant paid for the signage at move in on the initial lease, but I'm responsible for electricity and maintenance, as the signage is well lit at night. 

How would one get extra income from this?