Search engine optimisation (SEO)

One of the most important factors for determining a website's ranking in search engine results is the number of high quality relevant links from other websites to that site. These are known as backlinks. Google in particular uses backlinks to determine rankings in its PageRank system. Yahoo! and Bing also use it as one of several factors affecting their rankings.

Website owners should be aware of Google's recent updates which impacted the rankings of websites that violated Google's webmaster guidelines. These updates outlawed several widely used 'black hat' SEO techniques which involved artificially increasing the ranking of a webpage by manipulating the number of links pointing to the page.

Quality backlinks

A successful link-building strategy should be primarily about the quality of incoming links. A backlink is most valuable when:

• it comes from a respected site with a high page ranking of its own
• the website is relevant to your own

Link building tactics

You could build backlinks by:

• Building reciprocal links with partner sites - ie they will include links to you in return for links back to them. Businesses can link to their clients, suppliers and other businesses they work with in the form of recommendations or case studies. For example, a wedding venue business might link to recommended florists, make-up artists and caterers. 
• Submitting your site to online directories and resource lists.
• Approaching media sites to cover interesting stories or press releases that link to your site.
• Offering to write guest content for other sites relevant to your subject area. Your contribution can include links back to your own website. 
• Link baiting - including attention-catching 'viral' content to encourage social media users and online journalists to talk about your brand and link through to your site.
• Employing an agency to build links for you. It's important to choose the right partner, as it can have a significant effect on your success. If they use manipulative 'black-hat' techniques, it could lead to you being penalised or even de-indexed. For more information, see choosing a search engine optimisation agency.

Ultimately, having high-quality content on your site will encourage others to link to it.

Avoiding linkspam

Because of the importance of backlinks, some try to increase the number of links by any means possible, regardless of whether the linking is relevant. For example, by commenting on irrelevant forums just to post links or by using link-building software. These methods are considered 'black-hat' techniques intended to manipulate rankings and are not best practice and should be avoided.

Some search engines may also penalise your website or even remove it from the listings if too many backlinks are added in one day. Links from websites considered spam could penalise your website.

You should focus your efforts only on reputable websites that are relevant to your subject area. Links should appear naturally in the content and useful to users. 

For more details of manipulation tactics that are frowned upon, see search engine optimisation dos and don'ts.