Squire Rushnell is a former cable television executive, and his investigation into recorded example of synchromysticism reflects that experience pleasing an audience. There may be a sophisticated reason why people experience signposts within their subjective experience, but Rushnell doesn't go into that. For the suburban housewives who watch Good Morning America, these bite-sized stories about coincidences are all the entertainment they need. Bravo to Squire Rushnell for making a complex subject palatable to the average consumer.
I should note that Rushnell's God who winks does not belong to any established religion. Even when he talks about going to pray in church, or a Jewish couple meeting at a Jewish event, the religion is more like a backdrop that doesn't play into the story. Rushell's God winks could be described as the work of angels or the unconscious good-will of the universe, whatever concept satisfies the reader, as long as it evokes a kind of pronoia that makes you feel alright.
The advice will be useful if the reader has no prior experience with faith-trust in God/the Universe. Primarily it is designed to entertain (that is not a bad thing). The simplistic desire to entertain is why there have been over a dozen books on this subject, taking up the mantle of the Chicken Soup for the Soul series. The term "God wink" is too cute for me to want to use, personally, but I would buy this book as a gift for someone just becoming interested in spirituality.