Judging from an informal survey of the online Ultimate Strip Club List, there are more than 2,700 strip clubs in the United States. And enough money flows through these clubs that the Federal Reserve has taken notice, but not because of anything illegal.

Strip clubs nationwide have started giving two-dollar bills as change, a noteworthy new trend because few places other than strip clubs order the bills from their banks. The volume of cash transactions in strip clubs has begun to have a unique and trackable effect. According to Reuters (Nov. 6, 2006), depository institutions ordered $122 million in the unusual currency in 2005 alone. That's more than double the average yearly order between 1991 and 2000. The Federal Reserve first spotted the spike in 2001, when $92 million in orders for the two-dollar bill were processed. The numbers have continued climbing.

What gave strip clubs nationwide the idea to use the two-dollar bill as change? The answer might lie in Dallas, home to more than 20 strip clubs, several of them nationally recognized. At Baby Dolls Dallas, giving change in two-dollar bills is a 15-year-old tradition. Most people in Dallas assume that if you have a pocketful of two-dollar bills, you've been to Baby Dolls. This reputation impels men to rid themselves of the pesky bills before they leave the club, which leaves the workers in the club a little flusher.

Customers often handle the bills with disdain and get rid of them by overtipping waitresses, and not just because of their association with strip clubs; the unusual denomination also makes it hard for them to do the math while they're drinking. A man who would never dream of tipping a stage dancer two one-dollar bills will quickly hand over one or two two-dollar bills. He doesn't see them as 'real' money because they look different and aren't in common circulation. For their part, club workers may groan about the awkwardness of using the bills in a store (the currency often stumps clerks), but that doesn't stop them from accepting them as tips.