Bicycling

What has Tiger done for golf, or Michael Jordan for basketball? Lance probably added hundreds of millions of dollars to the take on TV alone. Then there is merchandising, endorsements, and the ineffable value of interest in the sport, which boosted sales of products Lance wasn't even directly associated with.

Here is something which may give you a general feel:

(Reuters) - The Versus sports cable TV network is shifting into higher gear as the comeback of seven-time Tour de France winner Lance Armstrong pulls in more U.S. viewers for the noted bicycle road race.

<>

Through the first nine days of the Tour, Versus viewer numbers are up 83 percent from last year, as well as 18 percent from 2005 when Armstrong last raced. In addition, traffic on Versus.com has soared 131 percent and the website has generated 6 million video views compared with 6.5 million for the entire race last year."

http://www.reuters.com/article/2009/07/15/us-versus-idUSTRE56E8IB20090715

IMO it's entirely reasonable to assume Lance was responsible for an 18% increase in cycling interest in the U.S., and all the money that that entails. Internationally, he probably increased interest but percentage-wise, in the low single digits.