$465 billion in 2008 - Dean Kamen towards the end of his TEDMED 2010 presentation. See link below at 58:02
$200 billion, according to Terry Rhoads, a former Nike marketing executive who is general manager of Zou Marketing, a Shanghai company that advises on sports management and promotion. Source added below.
"the personal consumption expenditure (PCE) on the spectator sports segment reached $25.4 billion" - WR HAMBRECHT + CO, a full-service investment bank, in its 2012 report. Source added below.
