In downtown Nashville, you can easily tell the 10,000 or so American Idol contestants in their jeans and flip flops apart from the 7,600 high school students dressed in dark suits and dress shoes attending a national Future Business Leaders of America convention.

But to hotel and retail owners, their money looks all the same and it means a busier and more lucrative spurt of sales. “Business has increased about 5 percent,” since Wednesday when the America Idol crowd first descended on Bridgestone Arena for tryouts, said Barbara McGuire, a sales associate at Lower Broadway’s Betty Boots, a women’s boutique.

The two large groups are expected to pump about $20 million in visitor spending into the city, rivaling this year’s July 4th weekend and bringing in about twice what a normal summer week would see from out-of-towners, said Butch Spyridon, president and CEO of the Nashville Convention & Visitors Bureau.

Spending patterns are a bit different because both groups skew young, so there’s not as much high-end dining on expense accounts or alcohol purchases, Spyridon said. “But it’s still good business for the city at a much-needed time,” he said.