Raincheck

[barrington]

Just in case you were wondering, as I was, where that comes from, it's actually pretty straightforward. Here's a definition from http://www.hometravelagency.com:

raincheck. A slip or chit given to a customer in compensation for services promised but not received, usually redeemable for the identical service at a later date. For example, patrons of a rained-out sporting event will receive a coupon good for admission to a game later in the season.