Are stimuli other than independent variables that may affect the outcome of the study and lead to erroneous conclusions.

acid rain is the answer

in this scenario it would be the consumer demand as most influential in making the decision. the band members need to figure out where and from whom they will make the most money, in other words who out of the two consumer groups - football fans or car drivers - will spend their money, who is more likely to contribute to their cause and buy what they are offering.