You might think that building a relationship and building a company are two difficult challenges best pursued at different times of your life. But Brian Phillips has figured out how to align both those interests. Brian, who happens to be single, is the CEO and co-founder of online dating site Thread.

In this segment of "Lessons for Entrepreneurs," Brian, a former PayPal product manager and who co-founded a payment platform Groovy.com back in the late 90's, shares three pieces of advice to fellow entrepreneurs.

"First, do something you’re passionate about. I’m single, many of my friends are single," he said. "We’re all passionate about dating. My business and personal interests are aligned."

Brian's second piece of advice is to work with people you love. Six out of the eight employees have worked at PayPal prior to Thread, he said. Two others worked at YouTube together. In fact, the team got together before they even had an idea.

Brian's third piece of advice is to attack a problem that already has organic demand. 

Finally, Brian shares his lessons from a company he started called Groovi.com, a pioneer of Web-based authentication services that competed with PayPal back in the Internet boom years. The company never gained much traction and Brian eventually went to work for PayPal.