An interesting experiment. Write an Instagram follower a message every day for one hundred days. You have not met this person except through your Instagram accounts. You have all of the author’s messages, but none from the recipient. There is only one reference to her ever replying and some questions are asked and asked again without and answer. The book shows some insight into our modern world of communications and of who we call “friends” as well as what we are willing to tell a complete stranger online. A nice concept for a book.
Evilcyclist's Bookshelf 
Reminds me a little of PostSecret a little but with a continuous thread,