Major League Baseball (MLB) is the oldest professional sports league in the United States and consists of 30 member clubs in the U.S. and Canada, representing the highest level of professional baseball. Under the guidance of its ninth Commissioner, Allan H. (Bud) Selig, MLB has experienced dramatic changes, including the introductions of Interleague Play, the Wild Cards and the expanded Postseason format; significant revenue sharing among the clubs; competitive balance on the field; the most comprehensive drug-testing program in American professional sports; and growth in revenue from $1.2 billion in 1992 to more than $7.5 billion in 2012. The last nine seasons are the nine best-attended years by fans in MLB history, with each year eclipsing the 73 million mark. MLB remains committed to making an impact in the communities of the U.S., Canada and throughout the world, perpetuating the sport's larger role in society and permeating every facet of baseball's business, marketing and community relations endeavors. With the continued success of MLB Advanced Media and MLB Network, MLB continues to find innovative ways for its fans to enjoy the National Pastime.