If you've RSVP'd for a party or a conference online, chances are you know Eventbrite. Last year, the digital ticketing platform reached a $1 billion valuation. It was the culmination of a journey that began less than 10 years ago when co-founders Julia and Kevin Hartz, then engaged, decided to commit not only to each other, but to a business. 

A television producer, Julia was between jobs in 2006. Before accepting a new offer, Kevin asked her to make an unconventional career move and start a company with him. She agreed, and they began to build their business with a third co-founder, Eventbrite CTO Renaud Visage. 

From there, it was hardly smooth sailing. Less than two years later, the economy plunged into a recession and startup capital was nowhere to be found. Still, Eventbrite plugged away and reached several memorable moments in the process--like the time it hosted 60,000 people for a 2011 Black Eyed Peas concert in Central Park.

Last year, amid speculation that the company would soon go public, Eventbrite instead opted to raise more funding--a move that ushered it into the Billion Dollar Startup Club. So is an IPO the next milestone for Eventbrite in 2015? Stayed tuned.