Hi, I want to ask the Rank and PR can actually important? Why your website: http://www.maylocnuoc.info.vn have PR = 4 that the word "may loc nuoc" its not the top one, while a top site for this tag again inferior to their website both PR and Alexa rank. In summary: - Site page rank, alexa rank is not high on the top 1 keyword. - Site page rank, alexa low standing top 1 keyword. So why?
can you check the number of searches permonth for that keyword and competiton ... try www.rankpay.com for serp rank check
My dear friend, Your website title :Máy lá»c nước | may loc nuoc nano Geyser | Lh Hà Ná»™i: 0946.538.556 is not good. You should have to write new title, which should be naturally and you can add some main keywords in professional way.