I have read many a monad tutorials. I'm reading through your new book right now and the chapter on IO is one of the best onramps I've read on building up intution for Monads!

Writing a book is hard work. Thank you for all the hardwork you put in writing this book, it's great! (I haven't gotten to the Monad Transformers yet in the book, I hope your book can finally help me get over the hump in understanding them :-)