
Wikipedia describes Cause Marketing as "a type of marketing involving the cooperative efforts of a "for profit" business and a non-profit organization for mutual benefit." The wiki author also ascribes credit to American Express, which first used the term to "describe efforts to support locally based charitable causes in a way that also promoted business."
Cause marketing has long been regarded as a great example of mutually beneficial corporate benevolence; The organization or people on the receiving end benefit, as does the corporation supporting them. In the case of the Forbidden City, we can assume the Chinese government or a restoration committee received funds to restore or preserve the building, and others like it throughout the palace compound. Clearly, they benefited. What did American Express gain? Given the millions of tourists and native Chinese who pass through those walls, one might assume the sponsorship created millions of global consumers who now have a positive association with the brand.
If they had chosen to ONLY support this one institution, we could perhaps fault American Express for supporting a communist regime, or question whether this was the most deserving beneficiary. But, in fact it was probably part of a much larger effort: The World Monuments Fund, of which American Express is a key sponsor. By pursuing a partnership with scale, they've done more than create a bit of goodwill among Forbidden City visitors; They've established themselves as a global, culturally enlightened and enlivened brand.