Christianity

A business that started a few centuries after a regular dude named Joshua got nailed to some 4x4s. Has grown and become an extremely affluent and successful business, largely due to its expansion during the crusades and the genocide of anybody who didn't want to join their customer base and give them money. It retains its large customer base to this very day through threats of eternal damnation if anybody believe differently or violates any of their rules. This manner of threat tends to breed fanatics who not only push their religion on others, but condemn those who don't believe as they do. Another method of customer retention is by controlling their customers' thoughts and actions. By doing this, they promote meekness, which in turn breeds people who need the church to tell them what to do day to day, and how to do it. For example, by condemning those for doing a perfectly natural thing such as having sex outside of a generic union that was invented by them (as another method of control), the church gets a grasp on their clients' natural instincts. This is paramount to controlling them. In summary, Christianity is a business that has been around for a long time, and has flourished by threatening and controlling its customers, and by the extermination of anybody who didn't want to buy their product.