containing 16,000 francs in gold and the diamonds of a late marchioness. The modern day transnational scam can be traced back to Germany in 1922 and became popular during the 1980s. There are many variants of the template letter. One of these, sent via postal mail, was addressed to a woman's husband to inquire about his health. It then asked what to do with profits from a $24.6 million investment and ended with a telephone number. Other official-looking letters were sent from a writer who said he was a director of the state-owned Nigerian National Petroleum Corporation. He said he wanted to transfer $20 million to the recipient's bank account—money that was budgeted but was never spent. In exchange for transferring the funds out of Nigeria, the recipient would keep 30% of the total. To get the process started, the scammer asked for a few sheets of the company's letterhead, bank account numbers, and other personal information. Yet other variants have involved mention of a Nigerian prince or other member of a royal family seeking to transfer large sums of money out of the country—thus, these scams are sometimes called "Nigerian Prince emails". The spread of e-mail and email harvesting software significantly lowered the cost of sending scam letters by using the Internet in lieu of international post. Nigeria is most often the nation referred to in these scams, they may originate in other nations as well. For example, in 2007, the head of the Economic and Financial Crimes Commission stated that scam emails more frequently originated in African countries or in Eastern Europe. Within the European Union, there is a high incidence of advance-fee fraud in the Netherlands and Spain. According to Cormac Herley, a Microsoft researcher, "By sending an email that repels all but the most gullible, the scammer gets the most promising marks to self-select." Responding to Herley, a director at Nigeria's National Security Adviser said that there are more non-Nigerian scammers claiming to be Nigerian, and suggested that Nigeria's reputation for corruption is part of the allure that makes scams seem more plausible. Nigeria has a reputation for being at the center of email scammers. Modern variations include “sugar daddy/sugar momma” schemes, some of which involve advance-fee scamming, and money flipping, whereby the mark is promised a large amount of money in exchange for sending a small amount of money. A 2018 study of Nigerian hip-hop