Dark patterns are often justified as trying to gain more of a user’s/customer’s attention, as seen to be the case here. IMHO, this is Amazon shrewdly introducing limits to their charity.

Whether it be a functional constraint or a dark pattern, user’s attention is being exchanged for agency of charity on behalf of the consumer.

A quick search on Twitter leads me to believe there is a feedback cycle Amazon leveraged with notifications about the Smile program. Consumers buy, notifications of their charity are pushed, Amazon profits. Repeat cycle. Amazon profits.