Chalk and cheese, Shimrod. The Harry Potter stories are for kids. The Terry Pratchett ones began masquerading as such, but they were always for adults. The pretense has been dropped now.

Harry Potter stories are about adventure. Terry Pratchet stories are about biting humour, taking the piss of everything and everyone that catches his attention, from mathematicians to filmmakers to police to religious fanatics, to ordinary folks' little quirks.

Rawlings made the millions, but Pratchet wrote the classics.