“Open access is often argued about in the abstract. I want to talk about a specific case study where I have detailed data – usage patterns for my (open access) online book/monograph “Neural Networks and Deep Learning” http://neuralnetworksanddeeplearning.com/chap1.html …
Would any of this have been possible closed access? Of course some of it would have. I might have made more money. But on nearly every other metric, I suspect being open access was a 100x or more multiplier on the impact….
To sum up: open access makes material freely available to people who would otherwise never even hear about it. This amplifying effect is not small, it is enormous. And it applies in parts of the world woefully underserved by the existing publication system….
Some additional calibration data: an editor at a major academic press tells me great sales figures for a similar technical textbook in a “hot” field are typically about 5,000-10,000 a year. So open access has a factor 200x or more here….”