carrying out all the off page techniques like directory submission, social bookmarking, article and blog creation and their submission, etc. will help in increasing the backlinks, but at the same time if the keywords are well mapped in On page and while doing off page submissions you will get hype in a short time in the search engine (this should be done ethically with the best relevancy of the keywords) and then as the site gains popularity by gaining the number of visitors it helps in increasing the page rank. you can also hire experts from SEoclerks for increasing page rank at cheap rates.