In recent years, travel — cheap travel, specifically — has boomed. Like all booms it has its winners (including influencers and home-sharing platforms like Airbnb) and its losers (namely locals and the environment). Somewhere in that mix is The Points Guy, Brian Kelly, who runs a blog that helps visitors navigate the sprawling, knotty and complex world of travel and credit card rewards. Today on The Sunday Read, a look at the life and business of Mr. Kelly, a man who goes on vacation for a living.