Actually in the video, one of the teams did something similar. They went to a highly trafficked area on campus and offered to test bike tire pressures for free

Actually in the video, one of the teams did something similar. They went to a highly trafficked area on campus and offered to test bike tire pressures for free, then fill the tire up for a dollar if necessary. They had a great response from this, but soon learned that they could make even more money by asking for a "donation", instead of a dollar.