I took advantage of it.  Why not?  If you pay 8 bucks (!!!!!!) for stale oversalted popcorn, you might as well get the "free" refill.  The difference is that I didn't get any butter on mine, and I took it home and waited until the next day to eat the refill.  The fat douche behind the counter tried to give me butter after I said I didn't want any though.  I made him dump it out and get me another one.