Google has various factors for deciding Search Engine Rankings Page Rank is considered one of the most important factor, however, its importance is reduced in the current scenario
Who told you that your actual PR is 0 ? you can't know .. The PR checking tools and the green bare are updated once in a while by Google .. and it's not your actual PR .. your PR could jumped to 1 or 2, and you don't even know that until the next update .. in April probably ..