You can do that in the US as well, but it will cost more because you wouldn’t be agreeing to a fixed term. For example, my ISP charges $25 a month for 200 mb/s if you agree to a one-year term, but it’s $40 a month if you do not agree to a one-year term. And there’s also the added inconvenience of having to go to one of the ISP’s physical stores every month and put cash into their kiosk.