Ask HN: At 9 cents/GB downloaded, how can any company afford cloud computing?

I get it if you generate little traffic, but for any site that generates any substantial traffic, it seems like costs would rapidly go through the roof. Or am I missing some key understanding?

Or is it just that companies pay attention to pricing except for that critical little 9 cent line item?

So if your user watches a 1 gig video, that costs your company 9 cents? Seems like a lot of money.