What's the difference between Genre Roulette and Genre Busting?

Courtesy links.

I get the sense there's supposed to be a difference here, but I'm just not seeing it. They both just seem to be lists of any work that combines genres that normally don't go together. Am I missing something?

edited 11th Dec '10 3:38:10 PM by RavenWilder

Genre Roulette is stuff that change genre frequently, like a rapid-fire Genre Shift. Genre-Busting either combines two or more genre, or is something that doesn't quite fit into any really defined genre.

Perhaps the key difference is that Genre Roulette stuff has only one genre at a time, while Genre-Busting usually has more than genre or no genre at all at any time.

I could see an argument for Genre Roulette being a subtrope of Genre-Busting, but I can imagine stuff that qualifies for Genre-Busting but not Genre Roulette