How often do you need to buy new underwear? The last time I did so was sometime in the mid 1990s. They don't look as good as they used to but they still do the job. When it becomes a necessity to do so, most underwear can be bought pretty cheaply locally without paying for shipping costs. This seems rather fussy to me.
Mine say that too (40°C, a bit over body temperature, in case you are used to Fahrenheit). I wash them with 60°C though, which is the normal "near body clothing" washing temperature one should use.
Consumerist propaganda? I can't imagine many people taking it that seriously. I do, in fact, buy new underclothes every 2-3 months only because I prefer the unworn feel. I'm sure many would agree. Looks like a startup with a not-so-novel idea, but a nice ordering interface and hopefully nice ordering process that will succeed.
When is it okay to throw away a set of veteran underwear?
a. When it has turned the color of a dead whale and developed new holes so large that you're not sure which ones were originally intended for your legs.
b. When it is down to eight loosely connected underwear molecules and has to be handled with tweezers.
c. It is never okay to throw away veteran underwear. A real guy checks the garbage regularly in case somebody -- and we are not naming names, but this would be his wife -- is quietly trying to discard his underwear, which she is frankly jealous of, because the guy seems to have a more intimate relationship with it than with her.