hello PR and traffic are both different thing so if increase your website PR next update after that increase website traffic did you think..then it's wrong thing of you..
Yeah I agree focus on the Serps and don't worry about PR unless you really need to. It's really the Serps that matter, you will often see sites with a PR of 0 on page 1, and sites with a high PR much lower down the ranking. For me (and my clients) being seen is what counts. Dee
search engines not giving SERP rankings by luck or just looking the designs of the website. Rankings are based on how many quality related backlinks and how informative contents your site have.