studio in Switzerland.
Brokered programming is a significant portion of most U.S. Christian radio stations' revenue, with stations regularly selling
blocks of airtime to evangelists seeking an audience. Another revenue stream is solicitation of donations, either to the evangelists who buy the air time or to the stations or their owners themselves. In order to further encourage donations, certain evangelists may emphasize the
prosperity gospel, in which they preach that
tithing and donations to the ministry will result in financial blessings from God. Others may have special days of the year dedicated to fundraising, similar to many
NPR stations. Although the solicitation of donations and the sale of airtime may resemble a commercial enterprise, such actions do not necessarily constitute a
call to action, and thus this does not forbid them from airing on
noncommercial licensed stations in the U.S. A minority of stations, typically music stations, use the traditional model for music radio and allow traditional commercial advertising. Numerous religious broadcasters own many of their own stations. In the U.S., religious radio stations are exempt from certain rules requiring radio stations to have some local operations, which allows them to have massive networks of transmitters covering far larger areas than a radio station would otherwise be allowed and may not face the same restrictions on the number of signals a broadcaster can own within one geographic area. ==Radio formats==