How is Twilight a saga?

I'm very confused. How is Twilight in any way epic? All it is is two teenagers falling in lust together. How does it compare to REAL sagas - the Iliad, the Odyssey, et cetera? Was it just a ploy to make more people buy the books, because reading a 'saga' is better than reading a 'series?' If someone could shed some light on this, it'd be excellent. x.x