Of course, the fact that it's easy to publish on those platforms doesn't mean it's easy to make more than beer money on them. (And, truth be told, even a publishing contract for a book often doesn't mean you'll make a significant sum of money.)
My experience in the tech industry writing tech-ish books is that they've been very good for my career. Also. The direct money I've made from them has been a rounding error even though the one I've done through a publisher was apparently successful enough they asked me to do a new edition.
