The machines are efficient and, among other things, allow customers to consolidate value from several MetroCards into one. Furthermore, they are the only place in the subway system where riders can purchase the new $4 one-day unlimited ride "fun" pass.

The machines accept credit and debit cards, introducing new conveniences and possibilities for riders. In a letter congratulating NYC Transit on the machines' advent and design, the Straphangers Campaign offered further ideas to help the MTA sell transit services.

First, use of credit cards to purchase fares opens the possibility that credit card companies could insure MetroCards against loss or theft. And if financial institutions can be engaged, they may facilitate "ride now/pay later" end-of-month billing for transit use.

Studies have shown that these kind of conveniences encourage people to use public transportation more, and MetroCard insurance and end-of-the-month MetroCard billing could increase the customer base of the financial institutions issuing the credit and debit cards.

The Transit Authority plans to install vending machines in all subway stations by the end of next year.