Restaurants use an electronic reservation book, and customers have access to its full inventory (though a block of tables can be set aside for unannounced regulars and celebrities).

CNN: Online restaurant reservations really do work

OpenTable ventured across the Atlantic with its Electronic Reservation Book product offering for restaurants in the U.K. in 2004, and followed up by setting shop in Japan and Germany in 2006 and 2007 respectively.

FORBES: OpenTable Would Be Worth $70 If You Ignored Its International Business