External cues come in many shapes or forms. A search result in Google, a social media share, or a huge billboard can be an external cue. However, a friend can casually mention a new book, or we can see someone reading it on the train. Sometimes, they are huge billboards, or sometimes just a hint in an interview with a famous author.
Targeted e-mails are one of the best examples of external cues. If I get an e-mail from Amazon with a list of books to read on my Kindle, based on my previous shopping behaviors, chances are this will trigger my book buying behavior yet again. Based on the sheer number of books I buy, I will start to feel like a book addict.
Through the repetition of the cue-routine-reward process, ...
