There's a good website to look at if you want to make comparisons..
I think it's actually owned by Google. You can make relative comparisons between any website on there.
The caveat with that site is that the stats all come from a downloaded toolbar installed on users browsers. As such the sample size will be restricted. But it's still an interesting way to judge the traffic of a website and we've noticed that it does seem to match a lot of our own measured numbers too.