Clearly I have been reading all the wrong kinds of Marquis de Sade books. The stuff of his I've read seems to be less about sexy spankings and more about women being repeatedly punched in the face and then set upon by dogs.
I have a love for the sort of spanking cartoons that used to appear in 'racy' humour magazines in the 1950s and 60s.
Discovering the world of Fan Fiction was a breakthrough. Finding out that there were whole swathes of people who would dedicate time to writing scenarios in which other people's fictional characters shagged - and occasionally spanked - one another was a revelation.