Businesses are increasingly turning to electronic billboards, large plasma display screens and their own in-location narrowcasting networks (referred to in marketing as “digital signage”) to make their business case and sales pitch to customers and clients as a major part of their marketing efforts It is estimated that the number of sites hosting narrowcasting networks that market for third parties – these are not the displays and digital signs where a retailer promotes his or her own products – are expected to grow from the roughly 210,000 sites currently hosted in the retail, hospitality, hospital and transportation sectors where digital signs are most predominant, to over 850,000 by 2011