Active optical cables (AOCs) are projected to represent a rapidly expanding market according to a study by Information Gatekeepers. The report, "Active Optical Cables Market Report 2009," explains that growth will occur in 15 different market segments from a variety of different digital interfaces, including HDMI and USB interfaces. The market, which represents 2 million units in 2009, should grow to more than 74 million units by 2013. Revenue is expected to grow from current 2009 levels of about $100 million to $1.3 billion by 2010 and more than $8.9 billion by 2013.