@breizh I live in the US. Costco sells literal bricks of unsalted butter, in packs of four even. I like to freeze them until I need them, typically only keep half of a brick at hand in the fridge. And yes, they are in the fridge, that half brick is still the size of three sticks of butter, I'm not going to finish it any time soon. I don't use butter everyday in my life so a butter bell isn't practical, but I do bake enough that those bricks of butter are nice to have at hand. Again, it's all about control since baking certain things does require specific ratios of ingredients. Salt is added to help bring out the sweetness of, so using unsalted lets you control the amount of salt you use. Salt also has a noticeable effect on eggs when prepped in certain ways, so you have to use unsalted butter in these cases. It's really just a flavor thing, i mean sure I don't mind if my chocolate chip cookies are a bit salty but I do mind when my snicker doodles are.