Park's first start-up, Boston-based athenahealth, co-founded with  Jonathan Bush, created a huge success out of curing the headache of billing management for medical practices. Having resettled in Silicon Valley, Park recently launched Ventana, with Giovanni Colella. This time, Park is seeking to relieve the mystery of out-of-pocket costs for consumers. Ventana will give us the power to conduct price-sensitive shopping for our doctors and clinics, or specific services and medical procedures. Think: Travelocity for healthcare. Park also serves as an advisor to the social entrepreneurship incubator Ashoka, which delivers telemedicine and low-cost drugs and diagnostics to India's rural poor. Park was recently named a Senior Fellow at the Center for American Progress, where his work focuses on transforming the health industry through IT.

"When designing a health care startup, there are three criteria you need to meet. One, are you solving an important problem for a well-defined customer?  Two, even if your product isn't a financial one, is your customer financially better off if they have your product vs. if they don't?  Three, is there a network effect in what you are doing? Does your product become more valuable to each of your customers as you add more customers?  If you can say 'yes' to these three questions, you'll maximize the probability that your startup will succeed in the brutal [but] wonderful work of bringing innovations into our health care system."