To maintain public interest and grow their membership lists, environmental groups are having to become increasingly sophisticated marketers. For example, the Nature Conservancy is spending $1 million to pilot TV and print ads featuring Paul Newman in Portland, Ore., Denver, Colo., and Charlotte, N.C. The National Wildlife Federation recently joined McDonald’s for a Happy Meals promotion. NWF also lent its name to a promotion with BP/Amoco gas stations — when customers purchased at least eight gallons of gas, they could also get stuffed animals (Endangered Wildlife Friends!) with the NWF logo and the message that fossil fuel companies contribute to global warming.