What leverage were protesters in montgomery able to use against the bus company?

The reason that African American made use of leverage in montgemery to be used against the bus company because of the fact that nearly 2/3 of African Americans made use of public transportation in montgemery by which if the boycott was successful, there will be a loss in revenue by the bus company forcing them to desegregation. The tactics used was suggested by Ida B. Wells-Bernett.