The various search engines have different algorithms in order to establish which website appears higher in the SERPs (search engine ranking pages). Search engines such as Yahoo and Bing still rely predominantly on on-page factors such as correct HTML, metadata, and copywriting.
However, Google (the undoubted heavyweight of all the search engines) holds increased importance on backlinks (links from external websites pointing to yours).
Google uses Page Rank (PR) which is a link analysis algorithm, named after Larry Page (co-founder of Google). Page Rank is Google’s measure of the ‘importance’ of the webpage and has a numerical value assigned between 0-10 with 10 being the greatest possible page rank and 0 being the lowest. For example, the New York Times currently has a Page Rank of 7 whereas a new website will usually have 0.
In order to increase the Page Rank of your website, a backlink strategy must be undertaken. Here are some of the different methods used to obtain backlinks; we will discuss their basic merits and downfalls.

Link Exchange – Link exchanges have now been around for many years. Link exchange is basically when a webmaster requests a backlink from your website in return for a backlink from their website. A few years ago this method of creating backlinks was effective, today links of this nature hold little weight, and therefore your time is better spent looking at other methods of link building like PBNs (Private Blog Networks).
Article Marketing – Article websites such as EzineArticles will publish unique articles that you have written, in turn, you may have two self-serving links in the Authors resource box. This is a great way of building links, as it can also be viral. If your article is compelling enough, people will blog and use the article elsewhere, thereby virally increasing the number of links obtained from the article. Remember, the article must be original and informative otherwise it may not get published, and even if it does it could have a detrimental effect on your business if the content is not good.
Blogging – We all know what blogs are and how effective they can be. The idea here is to start your own blog (Blogger or WordPress are the two main blog sites), make sure you update it regularly and create interesting and compelling content. A blog can then get a life of its own, earning Page Rank and ultimately allowing you to create backlinks to your website.
Social Bookmarks – Social bookmarking websites like Del.icio.us, Reddit, Digg, Furl, and StumbleUpon (there are lots of others) basically allow users to bookmark pages on the Internet that they are interested in. Social bookmarks are however public, therefore the more people that bookmark your website the more popular it will become, and therefore the rank will increase.
NOTE: Please never buy backlinks from a service provider on Fiverr.com. They can only get your site into trouble as most of these “gigs” use bots and will not be recognized by Google and can do much more harm than good.