Amazon's board loses Silicon Valley entrepreneur Krikorian SAN FRANCISCO (Reuters) - Silicon Valley entrepreneur and investor Blake Krikorian has quit the board of Amazon.com Inc about a year and a half after joining, the Internet company said on Friday without stating why. Krikorian, known for co-founding Sling Media in 2004, informed the rest of the board on Wednesday of his intention to resign, Amazon said. He joined the board in September of last year, according to his LinkedIn profile. The company was not immediately available for comment. Reporting By Edwin Chan; Editing by Gary Hill