A homophone is a word that sounds like another word, but has a different meaning and spelling. 

For example, write and right are homophones.

When potential customers see or hear one, it can cause them to think of the other-and any behaviors that are associated with it.

Homophones can prompt potential customers to think of the other word in the pair, and actions associated with it. That's why bye-bye or goodbye can prime someone to buy.