I agree, it's the 'fantasy' element that is key. I find a good snuff story very erotic, especially nc and nasty ones. For me it represents one of the most potent acts in erotic fiction, I can entirely divorce this from reality, (although I initially found my fantasies extremely disturbing) as I believe we define ourselves by what we DO rather than what we THINK and I find myself doing the opposite in real life. The way I see it is that you get the best of both worlds this way.