The company is on track to generate over $500 million in gross bookings this year, a 600 percent increase over 2015. "Vacation rentals are one of the largest and fastest-growing markets on the planet. By 2025 it’s estimated to be about $285 billion in terms of market size just for vacation rentals," said Tripping.com co-founder and CEO Jen O'Neal . "We’re very lucky to be playing in this massive and very hot market right now." Tripping.com was founded in 2011 to fill a "massive gaping hole" in the vacation rental market. While companies like Airbnb and HomeAway were hosting home-sharing and vacation rental listings, there was no company that aggregated all this inventory into one place. So O'Neal and co-founder Jeff Manheimer started Tripping.com, a metasearch engine that partners with other rental sites including HomeAway, VRBO, TripAdvisor, Booking.com and more. Get the full story at San Francisco Business Times