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If you want to get referral traffic without paying any money you should try guest posting. Guest posting is one the best ways which will help you to get referral traffic to your blog. If you having vast knowledge about any topic share it with others. Find the websites which are similar to you websites and are having a higher page rank so that you can get visitors from that website. Share your knowledge with the visitors of that website. Attract them with your words so that they are compelled to visit your website for more content.
Blog commenting is other great way of getting referral traffic. Comment on the blogs which are similar to your blog and are having a higher page rank. Reply on the posts on the blogs which you have already covered and then leave the link of the post covered in your topic in the comment so that you can get traffic to your blog. This will help you in getting referral traffic as well as will help in building traffic.
Yahoo Answering is one great way of getting referral traffic. Every day there are a lot of questions asked by people on Yahoo Answers. Solve the queries of the people and provide the link of your website in reference. Keep in mind not to spam otherwise Yahoo will your account and will take over all your answers.