Guest blogging
Guest blogging is one of the most popular and reliable source of getting quality backlinks. First you need to find related or similar to your niches, and then guest post some self written content having backlinks to your website pages. Ofcourse, the link should be logically defined and it is blog owner wish to honor that content and link. Also, be careful while choosing the blog or website you want to guest post for. Check the website rank and traffic statistics before forwarding your hardwork to them.
Giving free stuffs
This is an old marketing strategy. You give something for free and in return you ask for references. Though the result is not quick, but it will give you backlinks in long run. Some companies distribute free themes and post backlink to their website in footer section. You can also try same or some other ways to get backlinks. Some people include invisible links into themes in hope of gaining backlinks. Well, do I need to tell you that this kind of cleverness caught very soon and hardly anyone use that free stuffs. Just be transparent and ask as a request not to remove reference link from the footer. Trust me; many people will give you this favor.
Social Network
No one can deny the importance of social network on internet. This is a open market having billions of people together. Information on social network spread with the speed of light. You can create your own community and groups over there and can get exposure to your work much broadly.
Experiments
Experiments are very time consuming and result is not definite. People hate to waste their time on doing experiments. But you know people love to know the result of experiments. Do some experiment or survey and reach to the audience with results. Let them know the truth and how they can do some specific things better. Give all this favor to them for free. There would be big chances that many of them will give you back quality links.







