People with great bodies are always willing to shed their clothes for money--or for an important cause they believe in.
PETA has seen the publicity firsthand from featuring beautiful buff bodies au naturale, but the Olympics and cancer research and awareness groups have also seen their causes embraced as a reason to shed threads and have a picture taken for public consumption. Everybody wins.
Implications - Consumers are looking for ways to be titillated by ads. By showing without telling, marketers enable consumers to use their imaginations. Consumers that engage with ads on an imaginative level are active participants in the ads narrative instead of passive recipients of its key message.