For a multi-party advertising exchange including advertising and publishing entities, each participant specifies tax rate(s), such as import tax and export tax, that apply to at least one other entity in the exchange. Since tax rate(s) can be expressed in different transactional terms by different parties,...http://www.google.es/patents/US7698166?utm_source=gb-gplus-sharePatente US7698166 - Import/export tax to deal with ad trade deficits
