Today is Independence Day in the United States. Flags and fireworks fill stores ahead of the holiday.

For Valentine’s Day, we buy cards and roses.

For Halloween, we purchase costumes and candy.

My family baked me a chocolate cake for Father’s Day (the perfect gift this year).

All of those holidays were triggers for something else.

Jonah Berger talks about the power of triggers in his book Contagious. He says triggers work best when they are frequent and there is a strong link between trigger and the desired action.

The folks at Kit Kat found that people eat the candy bar during a break and with a hot beverage. They built an ad campaign called “a break’s best friend” that connected coffee and Kit Kats. The campaign was a hit and took the brand from $300 million to $500 million a year in sales.

Book publishing uses triggers too. In January, you will see publishers release titles that fit a “New Year, New You” themes like diet and personal empowerment. “Summer Reads” start to appear in May as readers make book picks for mid year vacations to the beach. And in September and October, the “big” books are released as everyone heads into the holiday gift giving season.

Is there something you can tie your book to?