Telethon

A telethon (a portmanteau of "television" and "marathon") is a televised fundraising event that lasts many hours or even days, the purpose of which is to raise money for a charitable, political or other purportedly worthy cause.

Most telethons feature heavy solicitations for pledges (promises to donate funds at a later time) combined with variety show style entertainment. The equivalent term for a radio broadcast is a radiothon; most radiothons do not include the entertainment.