I have found myself in the same situation as you. I average between 25-30 uniques (nothing to write home about) a day yet I have a google ranking of 5 and this is with about 10 pages of content (and gradually adding more). I don't understand this myself but at the same time I'm not going to complain. My Alexa ranking started at about 340,000 and has increased to 130,00 since I launched my site in April of this year. I can't explain why, maybe someone could explain this to us?