Eventful is an online calendar and events discovery service owned by CBS Corporation. The service allows users to search for and track upcoming entertainment events in their area (such as concerts, festivals, and film presentations) involving specific performers, indicate and share their intent to attend certain events, and indicate their "demand" for certain acts to appear in their region. Users can search for events worldwide by time, location, performer, and descriptive keyword. Users can create private or public calendars, including "smart" calendars which automatically update when events matching search criteria are added or existing events are modified. As of July 2007, the company claimed it had approximately 4 million future events in its search engine index. Users can optionally share their intention of attending an event with friends, and designate their favorite performers and venues to be used for recommendations. 'Eventful Demand allows users to declare an event or performance they would like to see locally, and then campaign for others to join their "demand". Statistics from "demands" can be used by event organizers to gauge interest in holding an event in that location.