Many people hire private operators.  Most charters are for a day or two, or a longer contract basis. The charter company provides the vehicles and qualified drivers. Charter bus operators may be completely independent businesses, or a subsidiary business of a public transport operator who might maintain a separate fleet or use surplus buses, coaches, and dual purpose coach seated buses. Many private taxicab companies also operate larger minibus vehicles to cater for group fares. Companies, private groups and social clubs may hire buses or coaches as a cost effective method of transporting a group to an event or site, such as a group meeting, racing event, or organized recreational activity such as a summer camps.

Entertainment or event companies may also hire temporary shuttles buses for transport at events such as festivals or conferences. Party buses are used by companies in a similar manner to limousine hire, for luxury private transport to social events or as a touring experience. Sleeper buses are used by bands or other organizations that tour between entertainment venues and require mobile rest and recreation facilities. Some couples hire buses for their wedding transport instead of the traditional car. Buses are often hired for parades or processions. Victory parades are often held for triumphant sports teams, who often tour their home town or city in an open-top bus. Sports teams may also contract out their transport to a team bus, for travel to away games, to a competition or to a final event. These buses are often specially decorated in a livery matching the team colors. Private companies often contract out private shuttle bus services, for transport of their customers or patrons, such as hotels, amusement parks, university campuses or private airport transfer services. This shuttle usage can be as transport between locations, or to and from parking lots. High specification luxury coaches are often chartered by companies for executive or VIP transport. Charter buses may also be used in Tourism and for promotion.

Cited from http://en.wikipedia.org/wiki/Bus