I remember when I lived in Geneva I never once paid for the use of public transportation. The two times I saw inspectors in the six months I was there I simply hopped off the bus, tram, or train before they got to me.
Is it like here where you just hop on the back of the bus? It's so stupid, there are never any inspectors here. For long articulated buses, you need to have proof of payment, so you can board the back of a bus if you have a transfer or a bus pass. However, since there are never any inspectors, everyone just boards the back of the bus whether they have proof of payment or not.