It must, but I assume once you get to a certain level of usage then an account manager / AWS gets you a slightly better than the publicly published deal. Is that the case?
Also, I wonder if EC2 is up for a price tweak soon too?
If you have a direct-billed account, and are spending more than 1,000/month, you'll get an automatic price break. At my current $DAYJOB, we're billing around $15-20K/month (depending on traffic) in Amazon Web Services charges, and I believe we're getting somewhere between a 10 and 25 percent price break.
Also, I wonder if EC2 is up for a price tweak soon too?
EDIT: Ah - https://news.ycombinator.com/item?id=7475284