One book that really changed my life was "Feeling Good" by David Burns. It kinda popularize Cognitive Behavioral Therapy. But the book wasn't an overnight success. It languished for years as his publisher refused to put any marketing dollars into it. They made it clear that his book wasn't really gonna get any love. Anyway, one day he got a call from Phil Donahue's producer. If I recall correctly, Burns had spent years doing any local spot he could get, and made it a point to be extra appreciative and grateful to anyone who interviewed him. One of these people went on to become one of Donahue's producers. (Donahue was in the class of Oprah back in the 80s and 90s). Overnight, his book became a huge success.

There's a lot of stories of 'overnight' successes actually being many many years in the making. Anyway, this was just one relevant one that came to mind reading this.