I know there are thousands of techniques to get backlinks right from directory submissions to commenting and much more. However usually mostly users ignore the technique of embedding the backlink in their product. That means you develop your own product such as Wordpress Theme, Worpdress Plugin (may be Free) and of course if the plugin has some innovative idea, hundreds of thousands of people will install that plugin on their blog and possibility is at the end of the day your website will rank high too. Also lot of people are giving free wordpress themes or plugins (developed by others) online and then behind the code they use their own backlink and once you install that paid plugin/theme indirectly you are giving them Free backlink. For example check the following website ( I am not owner/affiliate of it ) just giving you example, this person is giving free plugin but have his/her webpage rank 6 - which is huge - Code: http://charteredseo.com/ Hope it makes sense.