The 'grandfather of online dating' reveals the 3 crucial questions that can predict long-term compatibility in a relationship

"Traveling alone in a foreign country to me is like the most horrible possible thing I would ever want to do," Yagan said.

Yagan said he'd answer no for all three questions, though he's never had to do so in an online dating platform — he married his high school sweetheart and never used any of the dating services he created.