Isn't the 0% APR financing essentially just a sales expense? Even if people generally don't immediately roll into another 2-year agreement, the main reason these zero-interest financing works for the sellers is simply that it makes it easier for people to spend money on expensive high-margin stuff.

Multi-year zero-interest loans are also commonplace in high-price, high-margin specialty retail: think La-Z-Boy, Sleep Number, home improvement, hot tubs, home gym equipment, etc.