The whole Ebook business, real or scam?

Do you really make money off of Ebooks?

That's the question I asked myself while surfing the net and encountering literally hundreds of different Ebooks going from 10 bucks to 300 bucks.

Are Ebooks REALLY that monetizing?

Any of you out there making big chuncks of money with em? If so, how?

Cause what I often see is that awfull splash page with giagantic letters that say:

BUY THIS CRAP NOW and I'll tell you nothing new, just rip you off!

Thanks!