I was just wondering this, as I recently built my website but have started getting better ranks for certain terms in Google but still have PR0 I am currently getting an average of 50 unique visits per day
No, the number of visit doesn't help you in improving your SERP, if that's what your talking about, it work the other way around increase in SERP can increase your visitors.
backlinks will improve ur pr when google will update pr then maybe due to quality backlinks ur site will get good rank
Simple answer is no, however if you review the Google patent for it's search technology it does mention using visits as a method to rank search results; however this doesn't mean that its currently used in the algorithm and most likely isn't due to the possible abuse of this factor.
it could affect it butits not the deciding factor if you know what i mean? Building backlink and having great content is still what should be No 1 on your list
Here's an page from SEOmoz, http://www.seomoz.org/article/search-ranking-factors. If you scroll to the very bottom (the whole page has really good info) you'll see a pie graph showing how many SEO'ers believe this. I'm sure this has been posted before but it's very interesting.
How would Google monitor this information? Not every website uses Google services nor does every searcher, would produce invalid and inconsistant information making search results relevant to only a certain group of people.