Product review (4 stars): A touch pricey, but a good filter overall
These filters have an indeterminate lifespan in fridges which don't have water dispensers.  It's hard to tell whether the quality is really changing when you are only getting ice, so I just blindly follow the six-month warning light.  Working out the price, I may even save money if I buy bags of ice and dump them into the dispenser, but it's hard to beat the convenience, and that's what we're really funding here.

Blessedly, there are only two types of filters in Samsung fridges (at least as far as I can tell from their website) so if you have the long-skinny tube, this one is for you.  The quality of the filters really seems to be good in comparison to something mainstream (and terribly over-rated) like Britta.

Amazon is currently not selling these in-house, so I got mine from a third-party seller with free shipping.  It took a couple of weeks to get to me, but it is a genuine Samsung product as advertised.  Apparently, this was a big issue for a while.