Same thing further up north, in Norway.
But I get the impression that it's not like this in the US?
More people either buy in without a contract, or 2-year contracts?
The major carriers in the US are all set up for 2 year contracts, which come with subsidized phones. You can - technically - go month to month, but it's not a publicized or promoted feature, and doesn't come with substantial discounts.
There are alternatives - T-Mobile just came out with a $50/unlimited month-to-month plan - and there are some smaller carriers with month-to-month options, but they're the exception.