Recently, I had some tests run at a local hospital.  When I pulled into the parking ramp, I received a parking ticket.  When I entered the hospital, they validated the ticket.  So, when I left the parking ramp, I parked for free.

A couple of years back, I visited someone at that very hospital.  And as with my recent visit, my ticket was validated and I parked for free.

So my question is this.  If patients and visitors park for free, who actually pays to park there?