Heh. $DAYJOB lets us accrue vacation and then get cashed out annually for anything over 160 hours (so it is "use it or we will cash it out for you"). It pays out at your new rate as well (since annual raises are on the same schedule). It used to be tied to your work anniversary date, but it is now "just after New Year's" for everyone to make budgeting easier. I understand why companies hate it, but I also like the way I get treated as a human rather than a nameless cog in a multi-billion-a-quarter monstrosity. I, personally, prefer the "let's be human" than "$$$ at all costs" end of the spectrum. Others seem to disagree.

As for how it gets used, apparently it's very bimodal and "everyone" is either a "keeper" or "flirts with having none".