Facebook bought WhatsApp one year ago today. Here are 11 quotes from its billionaire cofounders

Exactly a year ago today WhatsApp cofounders Jan Koum and Brian Acton became filthy rich when they sold the company to Facebook for $19 billion five years after the app's launch.

Koum and Acton met while working as Yahoo engineers. They are both part of the "Facebook reject club." They hate advertising, and they feel strongly about having WhatsApp remain independent even though Facebook now owns it.

Koum moved to the US from communist Ukraine when he was 16. Acton was born in Michigan. Both are now billionaires.