Metlink has also been active in the use of ` value Metcards ' ( like credit cards but work only for trains ) and is known for running a `` funny '' campaign called BATBYGOBSTOPL ( Buying A Ticket Before You Get On Board Saves Time Or Problems Later ) . Metlink has also been active in encouraging use of ` value Metcards ' ( pre-purchased multi-trip and periodical tickets ) and is known for running a `` humorous '' campaign called BATBYGOBSTOPL ( Buying A Ticket Before You Get On Board Saves Time Or Problems Later ) .