@skaeth I have only intentionally done that once (I have a number of books that I intend to get back to, but probably never will). I am mad at the book - I invested 45 minutes before throwing it down. It was a fantasy book with a great world build and setup - except I concluded that if the next page switched to a Vogon telling telling the rest of the universe that everyone on the planet was like that and switched to some science fiction about building a hyperspace bypass the whole would be improved.
Otherwise if I invest the time to read more than 2 pages I want to finish it.