Real-time bidding (RTB) technology allows advertisers to purchase digital ad space through auctions that take place in milliseconds. RTB has grown rapidly since 2007, with 98 countries now supporting RTB and over 270 billion bid requests occurring in January 2011 alone. As RTB continues to expand, SSPs aim to integrate more user data directly into transactions to help advertisers better target impressions, identify valuable users, and span formats like mobile advertising through seamless private exchanges.