Celebrating its two-year anniversary in July, New York-based start-up ClassPass is challenging the traditional gym membership model. Instead of paying $50 a month to an all-purpose gym like 24 Hour Fitness or L.A. Fitness or $200 to $300 a month for CrossFit, ClassPass members get unlimited classes to participating boutique studios for $79 to $99 per month, with a maximum of three class per month at any one studio.The cost varies by city, and to date, more than 3,000 fitness studios in 34 cities in the U.S., Canada and U.K. have signed on. In May 2015, in Chicago alone, members booked more than 70,000 workout reservations at 230 studios, reported Crain’s Chicago Business. Members who want variety can take classes in cycling, Pilates, yoga, strength training, dance, martial arts, and more for one flat price with no long term commitment.Boutique studios benefit as well. New customers are introduced to their studios, and the owners get a cut of the revenue, though it is about half what they’d make if the customers joined their fitness studio outright. Jiya Williams, owner and instructor of Trophy Wife Fitness in Charlotte, North Carolina, told the Wall Street Journal her studio participates in ClassPass to draw new potential members. Since January, she converted two ClassPass subscribers to join her studio.”After six months, if it’s not beneficial and our conversion rates are not working out, then I would tell them ‘no, thank you,'” said Williams.ClassPass Co-Founder and Chief Executive Payal Kadakia acknowledged the conflict, “There’s a little bit of cannibalization that happens in the market. We understand that. The larger story here is that we’ve got people who would never walk in the door without something like ClassPass.”In just two years, ClassPass has been successful. Valued at more than $200 million in January, Kadakia told the Wall Street Journal that ClassPass is increasing its paychecks to studios each month and is paying for operating costs out of its $55 million in venture capital. It is also considering offering additional benefits to participating studios to help them fill classes.A few unnamed, participating studios told Crain’s, however, that they are concerned that ClassPass will drive prices down as studios compete with each other, causing them to lose steady clients.Insider Take:On the surface, ClassPass seems like an innovative idea that benefits studios and subscribers as well as ClassPass. Subscribers get variety and the opportunity to try out new studios, studios fill empty class slots while earning revenue, and ClassPass turns a profit to fuel future growth. For some studios and in some markets, the ClassPass subscription model may not work, but ClassPass has the potential to create strong partnerships with participating studios, giving studios the ability to be successful while remaining independent.