[Sicknero]

That's not nit-picking, it's an interesting comment in a thread which I thought wasn't stimulating any discussion :)

I disagree with Wiki's definition though on two counts really....

For instance a lot of advertising aims to generate feelings of fear, inadequacy and so on by playing on people's psychological processes and vulnerabilities, and so by that standard should be classified as horror.

On the other hand, I think a lot of horror (clearly not all) aims to stimulate a positive emotional reaction through escapism, the satisfaction of seeing "deserving cases" come to a gruesome end, and the vicarious thrill when the survivor wins through and escapes with the slasher/monster foiled or even destroyed.

I still think it comes down to an intent to entertain. I agree it's a very broad genre though and one not easily pinned down.