The idea came to Brandoff a couple of years ago when he was in Detroit as a Venture for America fellow and running business-to-business sales and advertising for Benzinga.com, a financial-media company. While volunteering at a basketball tournament, he noticed the rapt attention of parents of the boys and girls on the court — and realized the sales opportunity. He also recognized what companies wanting to reach that audience could do to help defray the cost of playing youth sports for families.