My top two most hit websites on the same shared server your site is on get a little more than 2 million and a couple hundred thousand hits respectfully per month. The #1 site that makes the millions of hits pays me back in their bandwidth costs through heavy advertising (they go through hundreds of gigabytes of traffic, (~300 GB on average, 450 on their worst month.) a month.) Adsense has recorded about 690,000 impressions since I was last paid. This system has been measured by my bandwidth provider transferring nearly 4 TB of data since December, (4,036 GB to be exact) and we've survived a few distributed denial of service attacks on a couple of websites. Some of those "bad bumps" have costed me quite a penny in overage fees.
Here's my bandwidth graph since I had the cacti service enabled on my port in September.
(I guess I don't have the ability to use img tags)
This graph is swapped, Outbound is traffic outbound the router, to my server, and vice versa, inbound is inbound to the router from my server.
Those big blue spikes are DDoS attacks, it sits low at only 5 mbit, due to the average of the traffic usually being below it, but the biggest spike was at least 200 mbit/sec. Costed me 24 GB of bandwidth every two minutes. That's an install of Windows 7 every minute.
I have a great relationship with my networking provider, so it fortunately all works out.
Lesson learned is to always prepare with a lot more bandwidth or the money on hand for it.
Edit:
http://i41.tinypic.com/dxzkec.png
This is what I got the last time I ran Webalizer on that #1 domain, I actually had to disable it because their access logs were getting up into tens of gigabytes, making generating webalizer take way too long. Actually, I'm not sure about whether or not this webalizer is 100% accurate, not sure about 700,000 hits a day. If this webalizer is right this site gets more like 20,000,000 hits. a month. But I don't know how accurate it is compared to Google Analytics or some other alternative.
The uniqs number a month sounds a bit more accurate though. I know this place gets a fair bit of google traffic, at least 5,000 impressions a day.