I am willing to bet that an average internet user visits less than a handful of sites per day. However, that is really a useless number. The real question is how many websites does an average person visit by entering the URL into their address bars. That number, I bet, is less than around 5 for an average user. 
For better or worse, I think the average user’s internet behavior is going to be shaped by a few sites. Sites like Facebook, Google, Yahoo, Twitter and maybe a few others.
So in reality, URL is kind of a weird technical artifact that is its losing importance as we convert them into tweets, stories on Digg, shares on Facebook and such. And for good reason; a URL is not something that’s easy to share, at least in real life.
What does this really all mean though? Not sure. I think although URLs are really some sort of a technical artifact of the initial design of the web, they have entered the common knowledge in forms of “addresses” or “links”. However, with alternate methods of accessing the information on the web such as finding things thru Facebook and iPad, I think the manual manipulation of URLs is going to go down. Instead, we might just enter in the URL for our favorite website (or hit their icon on our iPad or the Chrome OS) and then see where we go from there.
Maybe, one day, Apple will make a browser without a URL bar and we will all marvel at the simplicity of it.
1: I bet Mozilla has some good numbers on this. In fact, just writing this footnote reminded me of a web browser history project I was involved in while in college and reminded of a mock made by Mozilla’s own Alex Faaborg. It interestingly ties well with what I am saying in this essay.