There is a social cost imposed by society on people who fail to buy the trendy items.

If everyone's got hair scrunchies this year, not hair clips or hair ties, you had bet you'd better get an awesome scrunchie too or you're going to be the outcast, and bullied and picked-on even if you couldn't care less which thing you used to keep your hair out of the way.

If everyone had Keds last year and nobody has Keds this year because that's so last year, you'd better not show up wearing them either even if you couldn't care less what shoes you have as long as they work.

Most atheists are aware of the religious products because they need to be to lessen the social burden of failing to purchase the product. A few try to leverage it the other way around and gain social superiority. But for the most part, the reward is simply to be able to better avoid the social pressure to buy the product and gain more freedom to buy something else.