Taiwanese travel card, the EasyCard company is aggressive. After the announcement of working together with Singapore EZ-Link travel card, EasyCard to work with Hong Kong Octopus travelling card. One travelling card can be used in 3 cities (Taipei, Hong Kong and Singapore) in the future.
The idea is like telco roaming. You can use local register mobile phone in other countries, with roaming feature enable. With the "roaming" service, travellers don't have to get extra travelling card when they go to other country. There should be some technical issue to be solved, but the technical issues are not that difficult compare with the business decision.
The travelling card can be used for city train system (LRT, MRT), busses, parking or even used as a cash card to purchase goods. The payment are normally micro-payment. Malaysia has Touch'n Go card, Singapore has EZ-Link, Taipei has EasyCard (悠遊卡) and Hong Kong has Octopus card (八達通).
Malaysia Touch'n Go card can be used for parking, toll, LRT, Monorail, RapidKL bus, KTM train and ERL Train (train to KL International Airport). Touch'n Go card is not used for other payment system. In other countries like Hong Kong, Taipei and Singapore. The traveling card can be used as
Is convenience for consumer to travel by 1 card. As the travelling card can be used as payment card and cash card, there is still a lot of potential with travel card.