As an employer, I get some extra hours out of you and all it took was a few beers, or an Xbox, or a table game. That is a good investment for me, but not so good for you. It's the casino approach to maximizing profits. I'll give you free drinks and smokes, so stay a while.
My company's approach: We encourage people to wrap up their day at a healthy time, preferring to work smarter during our shorter days. We ask people in different time zones not to respond when getting chat/IM messages if it is outside of their work hours. They were doing this and it wasn't fair to them.
Despite this, our team puts in longer hours than we want because they are given challenging work and rise to the challenge. If we have to ask people to work extra time, as we did this week, we do it with the acknowledgement that we have had a lapse in planning on our part and we thank them for their commitment. Later, we go through and understand why we were unable to deliver and work on doing better with our planning.