The NCAA Division I Football Bowl Subdivision, formerly known as Division I-A, is the top level of college football in the United States. The FBS is the most competitive subdivision of NCAA Division I, which itself consists of the largest and most competitive schools in the National Collegiate Athletic Association. As of 2018, there are 10 conferences and 130 schools in FBS. College football is one of the most popular spectator sports throughout much of the United States, and the top schools generate tens of millions of dollars in yearly revenue. Top FBS teams draw tens of thousands of fans to games, and the ten largest American stadiums by capacity all host FBS teams or games. College athletes are not paid, but colleges are allowed to provide players with non-monetary compensation such as athletic scholarships that provide for tuition, housing, and books. Unlike other NCAA divisions and subdivisions, the NCAA does not officially award an FBS football national championship, nor does it sanction a playoff tournament to determine such a champion on the field.