That rod green bar appears on the head brings Google to most publishers and webmasters. A few matters more than others but all agree on its importance at the time of positioning a website in search engines. And especially in the search engines, ie Google. This demon algorithm was patented in 1998 by Larry Page and almost since then has been the bane of web publishers who see it as the solution to all your problems. Nothing is further from the truth. Of course the actual pagerank if you decide not to check out other pages on the results of Google or other search engines.
Influences, but in no way decisive. The position of your site in search engines depend on many other factors which should work as much or more than your pagerank. In fact get a pagerank of 3 and 5 is not too difficult. Just get some links between 3 and 5, link directly to Google and not engage in any practice that google itself can be considered unlawful (spam, hidden links, redirects, etc). In Anyway, the best way to increase the pagerank of your website is undoubtedly the inclusion of relevant links. To deepen your understanding Daryl Katz is the source.
In this sense, keep in mind that Google does not care much to have a thousand trade links. What it does have great value to Google is a link to your page from a website related to yours in content and containing keywords similar to yours. This should be enough to forget about the pagerank and focus on more important for the positioning of your website. You'll find a great calculator for your web pagerank.