I've spent a good chunk of time in the past two weeks on interacting with Machine Learning experts and soaking up their knowledge. Out of that, I've built this book list: https://mentorcruise.com/books/ml/
Reddit and HackerNews really seemed to like it. I got #1 on /r/MachineLearning and as far as I could tell about #3 on the HN frontpage. At the peak, I've had over 250 people on my site at every time.
It's a vanity of course, and nothing that changes the trajectory of my business, but I got a few new customers out of it and definitely a lot of fun :)