Japanese conglomerate Rakuten has pulled the plug on its U.S. online retail store, originally known as Buy.com, and will wind down its operations over the next two months, the company confirmed to TechCrunch. The shutdown means that the US headquarters will lay off its staff as well, meaning 87 people will lose their jobs, according a source familiar with the developments. “We have decided to sunset the U.S. Rakuten Marketplace,” a company representative said in an email to TechCrunch. They clarified, however, that the “cash back rewards” referral business the…