Reddit is on a roll. The self-styled "front page of the internet" is on target to double its ad revenue in the U.S. from $100 million in 2019 to $200 million in 2021, according to eMarketer. This growth is the result of tightening moderation on the platform and building out its advertising business. To discuss Reddit's evolution, strengths and next steps, chief operating officer Jen Wong joins the "Ad Lib" podcast—and questions host Brian Braiker's faith in humanity.