In addition to filing an S-1, first reported by AllThingsD, the company said that it had added several new members to its board of directors, including Jeffrey Housenbold, president and CEO of Shutterfly; Marne Levine, vice president of global public policy, Facebook; Richard Sarnoff, senior advisor of Kohlberg Kravis Roberts & Co (KKR); and Jed York, CEO of the San Francisco 49ers.