If you take mrt often, you might want to sign up at insinc here and receive rewards from all the travelling on the mrt!!
So far I've won $73. lol this might have something to do with the fact that I live in the east but school's in the west. Anyway, pretty worth it IMO since sign up is free and all you do is to set it to autoplay and win money. However, you will only win money frequently if you travel often over long distances.