The reasons for perpetrating hoaxes and forgeries range as widely as the kinds of fakes. Common motives for making bogus artifacts include publicity and self-promotion, monetary gain, practical jokes, and revenge, but some fakers have had the goal of supporting their own theories about the human past. Fakes have often been inspired by nationalism, with patriotic perpetrators boosting their country through spurious links to past civilizations.
People are taken in by hoaxes and fakes for many reasons. Successful bogus artifacts often match expectations or preconceived ideas of antiquities. Spectacular fakes have worked because those who buy them are blinded by their own pride of ownership--and the higher the price tag, the harder it is to make an embarrassing admission that it's a fake.
Shown is the Fawcett idol, which led Percy Fawcett to search for Atlantis in the jungles of South America. He never returned. Link -via Metafilter