Man, I've been referring to this phrase/term for the longest time without knowing what the proper naming of it is:
It's basically when whatever you're doing is artificially under priced because someone else is bearing the cost such as my zero percent credit card for 1 year (other people with high interest rates pay), the dollar beer at the local pub (those who get ultra drunk off the dollar beers and order the $100 bottle of Johnny Walker Blue) or, the one I feel most strongly about, the fact that someone can sit around spewing huge amounts of pollution and CO(2) into the air with no tax, since future generations actually pay the cost. Nice to have a definition on that finally wrapped up.