Since mars has an atmosphere, and it is composed mostly of a greenhouse gas, why isn't there a significant greenhouse effect to warm its surface?

While Mars' atmosphere is mostly CO2, a greenhouse gas, there isn't enough atmosphere to create an effective insulating layer to hold in the trapped IR radiation.

Explanation:

The remaining gases are a mixture of nitrogen, argon, oxygen and carbon monoxide. CO2 is a potent greenhouse gas, so Mars does have a greenhouse effect. But it's very weak because the Martian atmosphere is so thin -- 100 times less dense than the Earth's atmosphere.

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.