Every three months is the Google Pagerank

A page that has a high PageRank won't always beat a page with a lower PageRank. Matt Cutts explains why:
As a rule, Google tries to find pages that are both reputable and relevant. If two pages appear to have roughly the same amount of information matching a given query, we'll usually try to pick the page that more trusted websites have chosen to link to. Still, we'll often elevate a page with fewer links or lower PageRank if other signals suggest that the page is more relevant.

__________________
Email marketing and SEO