It depends a lot on topic/phrase - there is no average amount of page views. I have one page that I wrote when I first started here (I think it was my first hub) that was not optimized at all and I had chosen a crappy title that was not getting found in the search engines. It used to get 1 or 2 visits a day if I was lucky.
When I did some keyword research and found a better phrase to use in my title and throughout my text, summary etc the traffic went up over several months and now it gets about 100 views per day. It doesn't earn tonnes of money and probably never will, but it earns a lot more than it did before it was optimized and it's nice to know that my initial writing efforts weren't wasted because at least people are now reading what I wrote.