My grandmother kept a can of it on her stove, adding to it each time she cooked bacon, which was pretty much every day (working farm). Probably not safe or recommended by today's standards, but none of us ever died or even got sick from her practice.
Me, on the rare occasions when I do save it because I know I'm frying potatoes or some other use for it later in the week, I let it cool, put it in a container and refrigerate. I don't bother keeping any long term because I just don't have that much use for it.