Maybe it's not the best book on GraphQL, I don't know, but it is miles better than most paid tech-books out there.
The book is self-published and the author isn't well known, so he needs to something to build an audience. Giving them such a good book for an email is a nice way to do so.
I'm not well known either and my publisher only gives away one chapter for an email and then you have to buy it.
It's true!
Maybe it's not the best book on GraphQL, I don't know, but it is miles better than most paid tech-books out there.
The book is self-published and the author isn't well known, so he needs to something to build an audience. Giving them such a good book for an email is a nice way to do so.
I'm not well known either and my publisher only gives away one chapter for an email and then you have to buy it.