I asked Bryan Caplan what effect his blogging had had. It made his first book a success, he said. Or helped make it a success. He had started blogging about two years before it appeared. Other bloggers wrote about his book as if they knew him. They knew him from his blog.
I would not have known who you are except for Tyler Cowen linking to your paper on Marginal Revolution. That led to my reading your paper on self-experimentation, then your blog, and finally your book.
None of that would have happened though if the initial paper hadn’t been really good. It may be an obvious point, but I think it is worth saying explicitly: blogging (or any kind of marketing) will help an excellent product sell well; It will always be hard to sell trash.
(completely offtopic, feel free to delete)
This might interest you:
https://www.clapclap.org/2007/04/hallelujah.html