DETROIT (4/2/10)--Cash-strapped school districts in Detroit are presenting a marketing opportunity for credit unions by allowing advertisements on gym walls, athletic fields and school websites to help earn funds for the school districts. The key categories for ad sales include credit unions, banks, car dealers, quick-service foods, and fine dining restaurants, said Alternative Revenue Development, a Bloomfield Hills-based company that is selling the idea to schools. The first campaign will roll out at Trenton High School April 14, with three other Downriver districts participating. In August about 30 more school districts will begin displaying ads. Trenton-based Metro Shores CU said its ad campaign is half philanthropic, considering the state's funding crisis, but the ad campaign is expected to bring in business. The credit union has a sign on the school campus and website, and can set up a booth at sporting events to distribute brochures and talk to potential members The revenue generator comes amid a state funding crisis that is forcing school districts to get creative in making more revenue.